diff --git a/.github/workflows/brs-commit-checker.yml b/.github/workflows/brs-commit-checker.yml
index 111712e9968e..a46d1dbe6d54 100644
--- a/.github/workflows/brs-commit-checker.yml
+++ b/.github/workflows/brs-commit-checker.yml
@@ -21,7 +21,7 @@ jobs:
     commit-report:
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v5
+            - uses: actions/checkout@v6
               with:
                 fetch-tags: true
                 fetch-depth: 0
diff --git a/.github/workflows/cache_retain.yml b/.github/workflows/cache_retain.yml
index a88deb841190..40f9f4f3fc89 100644
--- a/.github/workflows/cache_retain.yml
+++ b/.github/workflows/cache_retain.yml
@@ -42,7 +42,7 @@ jobs:
     if: github.ref == 'refs/heads/main' && github.repository == 'unicode-org/unicodetools'
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: 'temurin'
diff --git a/.github/workflows/cifuzz.yml b/.github/workflows/cifuzz.yml
index 14142516fe87..6edb9d750353 100644
--- a/.github/workflows/cifuzz.yml
+++ b/.github/workflows/cifuzz.yml
@@ -55,7 +55,7 @@ jobs:
         path: ./out/artifacts   
     - name: Upload Sarif
       if: always() && steps.build.outcome == 'success'
-      uses: github/codeql-action/upload-sarif@v4.31.2
+      uses: github/codeql-action/upload-sarif@v4.31.6
       with:
         # Path to SARIF file relative to the root of the repository
         sarif_file: cifuzz-sarif/results.sarif
diff --git a/.github/workflows/icu4c.yml b/.github/workflows/icu4c.yml
index dc8fde7899d6..675767543a7b 100644
--- a/.github/workflows/icu4c.yml
+++ b/.github/workflows/icu4c.yml
@@ -47,7 +47,7 @@ jobs:
   icu4c-docs-build:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C doc
         run: |
@@ -70,7 +70,7 @@ jobs:
   gcc-debug-build-and-test:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C with gcc
         env:
@@ -97,7 +97,7 @@ jobs:
           - '-std=c++20'
           - '-std=c++23'
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Install GCC-14
         run: |
           sudo add-apt-repository ppa:ubuntu-toolchain-r/test
@@ -122,7 +122,7 @@ jobs:
   clang-release-build-and-test:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: Install doxygen
         run: |
@@ -170,7 +170,7 @@ jobs:
          # --disable-shared has a build problem.
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: Build ICU4C with clang
         run: |
@@ -186,7 +186,7 @@ jobs:
   gcc-10-stdlib17:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C with gcc 10 and c++17 and extra warnings.
         env:
@@ -207,7 +207,7 @@ jobs:
   clang-asan:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C with clang and asan
         run: |
@@ -221,7 +221,7 @@ jobs:
   clang-lsan:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C with clang and lsan
         run: |
@@ -236,7 +236,7 @@ jobs:
   clang-ubsan:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C with clang and ubsan +alignment
         run: |
@@ -251,7 +251,7 @@ jobs:
   clang-cfi:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C with clang using CFI
         run: |
@@ -270,7 +270,7 @@ jobs:
   clang-tsan:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C with clang and tsan
         run: |
@@ -292,7 +292,7 @@ jobs:
   clang-datafilter:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Extract ICU version
         run: |
           # Extract ICU version from icuver.txt
@@ -314,7 +314,7 @@ jobs:
   clang-cpp17:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Build ICU4C with CPP 17
         env:
           CXXFLAGS: -std=c++17 -Winvalid-constexpr
@@ -325,7 +325,7 @@ jobs:
   clang-lang-with-extn-tags:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Linux Clang - LANG has extension tags
         env:
           LANG: "en_US@calendar=gregorian;hours=h12"
@@ -354,7 +354,7 @@ jobs:
             - clang-version: '18'
               flags: '-std=c++20 -stdlib=libc++'
       steps:
-        - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
         - name: Install Modern Clang
           env:
             CLANG_VERSION: ${{ matrix.clang-version }}
@@ -375,7 +375,7 @@ jobs:
   macos-clang:
     runs-on: macos-15  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: ICU4C with clang on MacOS
         env:
           CPPFLAGS: '-Wall -Wextra -Wextra-semi -Wundef -Wnon-virtual-dtor -Wctad-maybe-unsupported -Wglobal-constructors -Wexit-time-destructors -Werror'
@@ -402,7 +402,7 @@ jobs:
           - test_flags: 'x64 Release'
             build_flags: '/p:Configuration=Release /p:Platform=x64'
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Set up MSBuild
         uses: microsoft/setup-msbuild@v2
       - name: Build Solution x64
@@ -421,7 +421,7 @@ jobs:
     runs-on: windows-2022  # Updated in BRS
     timeout-minutes: 30
     steps:
-    - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+    - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
     - name: Set ICU_DATA_FILTER_FILE variable
       run: |
         $filterPath = "${{ github.workspace }}\.github\data-filter.json"
@@ -452,7 +452,7 @@ jobs:
             plat: 'ARM64'
             win_ver: 'WinARM64'
     steps:
-    - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+    - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
     - name: Set up MSBuild
       uses: microsoft/setup-msbuild@v2
     - name: Build Solution x64
@@ -503,7 +503,7 @@ jobs:
       run:
         shell: msys2 {0}
     steps:
-    - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+    - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
     - name: Set up MSYS2
       uses: msys2/setup-msys2@v2
       id: msys2
@@ -536,7 +536,7 @@ jobs:
   run-with-stubdata:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C tests with stubdata
         run: |
@@ -579,7 +579,7 @@ jobs:
   u-charset-is-utf8-test:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - run: |
           cd icu4c/source;
           ./runConfigureICU Linux CPPFLAGS="-DU_CHARSET_IS_UTF8=1";
@@ -589,7 +589,7 @@ jobs:
   u-override-cxx-allocation-is-0-test:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - run: |
           cd icu4c/source;
           ./runConfigureICU Linux CPPFLAGS="-DU_OVERRIDE_CXX_ALLOCATION=0";
@@ -600,7 +600,7 @@ jobs:
   lstm-test:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - run: |
           cd icu4c/source;
           ICU_DATA_FILTER_FILE=../../.github/lstm_for_th_my.json ./runConfigureICU --enable-debug --disable-release Linux -disable-layoutex;
@@ -611,7 +611,7 @@ jobs:
   adaboost-test:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - run: |
           cd icu4c/source;
           ICU_DATA_FILTER_FILE=../../.github/adaboost.json CPPFLAGS=-DUCONFIG_USE_ML_PHRASE_BREAKING=1 ./runConfigureICU --enable-debug --disable-release Linux -disable-layoutex;
@@ -622,7 +622,7 @@ jobs:
   testmap:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - run: |
           cd icu4c/source;
           ./runConfigureICU Linux;
@@ -635,21 +635,21 @@ jobs:
   copyright-scan:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - run: perl tools/scripts/cpysearch/cpyscan.pl
 
   # Check compilation of internal headers.
   internal-header-compilation:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - run: cd icu4c/source; test/hdrtst/testinternalheaders.sh
 
   # Check source files for valid UTF-8 and for absence of BOM.
   valid-UTF-8-and-no-BOM-check:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - run: tools/scripts/icu-file-utf8-check.py
 
   # Run unit tests with UCONFIG_NO_XXX variations.
@@ -678,7 +678,7 @@ jobs:
          - "-DUCONFIG_NO_LEGACY_CONVERSION=1 -DUCONFIG_NO_NORMALIZATION=1 -DUCONFIG_NO_BREAK_ITERATION=1 -DUCONFIG_NO_IDNA=1 -DUCONFIG_NO_COLLATION=1 -DUCONFIG_NO_FORMATTING=1 -DUCONFIG_NO_MF2=1 -DUCONFIG_NO_TRANSLITERATION=1 -DUCONFIG_NO_REGULAR_EXPRESSIONS=1 -DUCONFIG_NO_SERVICE=1 -DUCONFIG_NO_FILTERED_BREAK_ITERATION=1"
     steps:
       - name: Checkout
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Verify no additional new UCONFIG_NO_xxx added
         run: |
           # Test that we have exactly 13 "#ifndef UCONFIG_NO_" in uconfig.h. If the number changes, we need to also
@@ -725,7 +725,7 @@ jobs:
          - "-DUCONFIG_NO_LEGACY_CONVERSION=1 -DUCONFIG_NO_NORMALIZATION=1 -DUCONFIG_NO_BREAK_ITERATION=1 -DUCONFIG_NO_IDNA=1 -DUCONFIG_NO_COLLATION=1 -DUCONFIG_NO_FORMATTING=1 -DUCONFIG_NO_MF2=1 -DUCONFIG_NO_TRANSLITERATION=1 -DUCONFIG_NO_REGULAR_EXPRESSIONS=1 -DUCONFIG_NO_SERVICE=1 -DUCONFIG_NO_FILTERED_BREAK_ITERATION=1"
     steps:
       - name: Checkout
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Verify no additional new UCONFIG_NO_xxx added
         run: |
           # Test that we have exactly 13 "#ifndef UCONFIG_NO_" in uconfig.h. If the number changes, we need to also
@@ -754,7 +754,7 @@ jobs:
   unicode-update-tools:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-    - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+    - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
     - uses: bazel-contrib/setup-bazel@0.15.0
     - name: Get CI Linux runner VM version
       id: linux-version
@@ -793,7 +793,7 @@ jobs:
   icu4c-test-samples:
       runs-on: ubuntu-22.04  # Updated in BRS
       steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: ICU4C configure and build
         run: |
@@ -818,7 +818,7 @@ jobs:
   icu4c-without-collation-rule-strings:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Install hjson dependency
         run: |
           sudo apt-get install python3-pip
@@ -858,7 +858,7 @@ jobs:
   icu4c-uconfig-no-conversion:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Set UCONFIG_NO_CONVERSION and configure ICU4C
         env:
           UCONFIG_NO_CONVERSION: 1
@@ -881,7 +881,7 @@ jobs:
       contents: write # So that we can upload to release
     timeout-minutes: 30
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Build
         run: |
           cd icu4c/source && ./runConfigureICU Linux && make -j -l4.5
diff --git a/.github/workflows/icu4j.yml b/.github/workflows/icu4j.yml
index f248e6c8af68..54f2b4cafe60 100644
--- a/.github/workflows/icu4j.yml
+++ b/.github/workflows/icu4j.yml
@@ -47,7 +47,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Cache local Maven repository
         uses: actions/cache@v4
         with:
@@ -74,7 +74,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0  # fetch all branches so that Spotless can resolve `origin/main`
       - name: Restore read-only cache of local Maven repository
@@ -102,7 +102,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Restore read-only cache of local Maven repository
         uses: actions/cache/restore@v4
         id: cache
@@ -131,7 +131,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Restore read-only cache of local Maven repository
         uses: actions/cache/restore@v4
         id: cache
@@ -168,7 +168,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Restore read-only cache of local Maven repository
         uses: actions/cache/restore@v4
         id: cache
diff --git a/.github/workflows/icu_common.yml b/.github/workflows/icu_common.yml
index 8203ac935387..40df0f32e597 100644
--- a/.github/workflows/icu_common.yml
+++ b/.github/workflows/icu_common.yml
@@ -35,14 +35,14 @@ jobs:
   copyright-scan:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - run: perl tools/scripts/cpysearch/cpyscan.pl
 
   # Check source files for valid UTF-8 and for absence of BOM.
   valid-UTF-8-and-no-BOM-check:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - run: tools/scripts/icu-file-utf8-check.py
 
   # Initialize the Maven artifact cache
@@ -53,7 +53,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Cache local Maven repository
         uses: actions/cache@v4
         with:
@@ -75,7 +75,7 @@ jobs:
     needs: icu4j-mvn-init-cache
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Restore read-only cache of local Maven repository
         uses: actions/cache/restore@v4
         id: cache
diff --git a/.github/workflows/icu_docs.yml b/.github/workflows/icu_docs.yml
index 9e1abaf1197b..9df823598161 100644
--- a/.github/workflows/icu_docs.yml
+++ b/.github/workflows/icu_docs.yml
@@ -40,7 +40,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1
         with:
diff --git a/.github/workflows/icu_envtest.yml b/.github/workflows/icu_envtest.yml
index 241ff5048cab..2d589bdb330c 100644
--- a/.github/workflows/icu_envtest.yml
+++ b/.github/workflows/icu_envtest.yml
@@ -46,7 +46,7 @@ jobs:
         run: |
           locale -a;
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Build
         run: |
           cd icu4c/source/;
@@ -105,7 +105,7 @@ jobs:
           find /usr/share/zoneinfo/ -type f,l|egrep -v "/(right|posix)/"|egrep -v "\.tab"|wc -l;
           find /usr/share/zoneinfo/ -type f,l|egrep -v "/(right|posix)/"|egrep -v "\.tab"|cut -d '/' -f5-50;
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Build
         run: |
           cd icu4c/source/;
diff --git a/.github/workflows/icu_exhaustive_tests.yml b/.github/workflows/icu_exhaustive_tests.yml
index cb91158f6b06..3c02aca12035 100644
--- a/.github/workflows/icu_exhaustive_tests.yml
+++ b/.github/workflows/icu_exhaustive_tests.yml
@@ -50,7 +50,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     timeout-minutes: 180
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Build and Run Exhaustive Tests
         run: |
           echo "Building ICU4J" && cd icu4j && mvn ${SHARED_MVN_ARGS} install -DICU.exhaustive=10
@@ -67,7 +67,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     timeout-minutes: 120
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Build
         run: |
           cd icu4c/source && ./runConfigureICU Linux/clang && make -j -l4.5
diff --git a/.github/workflows/icu_merge_ci.yml b/.github/workflows/icu_merge_ci.yml
index 08ad231cea59..5977a7607ac1 100644
--- a/.github/workflows/icu_merge_ci.yml
+++ b/.github/workflows/icu_merge_ci.yml
@@ -39,7 +39,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Cache local Maven repository
         uses: actions/cache@v4.2.0
         with:
@@ -61,7 +61,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Lookup read-only cache of local Maven repository
         uses: actions/cache@v4.2.0
         with:
@@ -91,7 +91,7 @@ jobs:
     if: github.repository == 'unicode-org/icu' && github.ref == 'refs/heads/main'
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: Build ICU libraries
         run: |
@@ -132,7 +132,7 @@ jobs:
 
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Create directory for lib files
         run: mkdir icu4c/source/perflib
       - name: Get ICU libs
@@ -206,7 +206,7 @@ jobs:
 
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Create directory for lib files
         run: mkdir icu4c/source/perflib
       - name: Get ICU libs
@@ -271,7 +271,7 @@ jobs:
 
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Create directory for lib files
         run: mkdir icu4c/source/perflib
       - name: Get ICU libs
@@ -321,7 +321,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Lookup read-only cache of local Maven repository
         uses: actions/cache@v4.2.0
         with:
@@ -375,7 +375,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Lookup read-only cache of local Maven repository
         uses: actions/cache@v4.2.0
         with:
@@ -431,7 +431,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Lookup read-only cache of local Maven repository
         uses: actions/cache@v4.2.0
         with:
@@ -492,7 +492,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Lookup read-only cache of local Maven repository
         uses: actions/cache@v4.2.0
         with:
@@ -623,7 +623,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Lookup read-only cache of local Maven repository
         uses: actions/cache@v4.2.0
         with:
@@ -698,7 +698,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout and setup
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Lookup read-only cache of local Maven repository
         uses: actions/cache@v4.2.0
         with:
@@ -753,7 +753,7 @@ jobs:
     needs: [icu4c-performance-tests, icu4c-performance-tests-with-files, icu4c-strsrchperf, icu4j-unicodesetperf, icu4j-ucharacterperf, icu4j-decimalformatperf, icu4j-normperf, icu4j-converterperf, icu4j-dateformatperf]
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
 
       - name: Switch to benchmark data storage branch.
         run: |
@@ -783,7 +783,7 @@ jobs:
           - arch: x64
             platform: x64
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Set up MSBuild
         uses: microsoft/setup-msbuild@v2
       - name: Build Solution
@@ -814,7 +814,7 @@ jobs:
       - name: Configure Git to checkout with Unix line endings (LF)
         run: |
           git config --global core.autocrlf input
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Restore Cygwin cache
         uses: actions/cache@v4
         with:
diff --git a/.github/workflows/icu_valgrind.yml b/.github/workflows/icu_valgrind.yml
index a9e94d60b3ef..db2cb690a910 100644
--- a/.github/workflows/icu_valgrind.yml
+++ b/.github/workflows/icu_valgrind.yml
@@ -42,7 +42,7 @@ jobs:
           sudo apt-get -y update;
           sudo apt-get install -y valgrind;
       - name: Checkout
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Build with debug enable
         env:
           CC: clang
@@ -87,7 +87,7 @@ jobs:
           sudo apt-get -y update;
           sudo apt-get install -y valgrind;
       - name: Checkout
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Build with debug enable
         env:
           CC: clang
diff --git a/.github/workflows/jekyll-gh-pages.yml b/.github/workflows/jekyll-gh-pages.yml
index f0db1042a802..c544316c56eb 100644
--- a/.github/workflows/jekyll-gh-pages.yml
+++ b/.github/workflows/jekyll-gh-pages.yml
@@ -37,7 +37,7 @@ jobs:
     runs-on: ubuntu-22.04  # Updated in BRS
     steps:
       - name: Checkout
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - name: Setup Ruby
         uses: ruby/setup-ruby@8575951200e472d5f2d95c625da0c7bec8217c42 # v1.161.0
         with:
diff --git a/.github/workflows/maven.yaml b/.github/workflows/maven.yaml
index 20b9b3968369..24305beaac17 100644
--- a/.github/workflows/maven.yaml
+++ b/.github/workflows/maven.yaml
@@ -21,7 +21,7 @@ jobs:
       version: ${{ steps.mvn-proj-version.outputs.version }}
       version-type: ${{ steps.mvn-proj-version-type.outputs.version-type }}
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+      - uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
       - uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: 'temurin'
diff --git a/.github/workflows/release-check-sign.yml b/.github/workflows/release-check-sign.yml
index 66ef47c557fe..d19217c33a47 100644
--- a/.github/workflows/release-check-sign.yml
+++ b/.github/workflows/release-check-sign.yml
@@ -22,7 +22,7 @@ jobs:
     steps:
 
     - name: Checkout and setup
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Set up JDK
       uses: actions/setup-java@v5
diff --git a/.github/workflows/release-icu4c-fedora.yml b/.github/workflows/release-icu4c-fedora.yml
index 97a3647562e3..6c0b3a7eff75 100644
--- a/.github/workflows/release-icu4c-fedora.yml
+++ b/.github/workflows/release-icu4c-fedora.yml
@@ -36,7 +36,7 @@ jobs:
         dnf install -y gh
 
     - name: Checkout and setup
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Config and build ICU4C proper
       run: |
diff --git a/.github/workflows/release-icu4c-ubuntu.yml b/.github/workflows/release-icu4c-ubuntu.yml
index 105316fd1600..8c55b082fc7d 100644
--- a/.github/workflows/release-icu4c-ubuntu.yml
+++ b/.github/workflows/release-icu4c-ubuntu.yml
@@ -29,7 +29,7 @@ jobs:
         sudo apt-get -y install doxygen
 
     - name: Checkout and setup
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Config and build ICU4C proper
       run: |
diff --git a/.github/workflows/release-icu4j-maven.yml b/.github/workflows/release-icu4j-maven.yml
index 05800975dcd4..8217d0086168 100644
--- a/.github/workflows/release-icu4j-maven.yml
+++ b/.github/workflows/release-icu4j-maven.yml
@@ -48,7 +48,7 @@ jobs:
     steps:
 
     - name: Checkout repo files
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Set up JDK
       uses: actions/setup-java@v5
diff --git a/.github/workflows/scorecard.yml b/.github/workflows/scorecard.yml
index 60b91a839fe2..c90747caf895 100644
--- a/.github/workflows/scorecard.yml
+++ b/.github/workflows/scorecard.yml
@@ -29,7 +29,7 @@ jobs:
 
     steps:
       - name: "Checkout code"
-        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.1
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v4.1.1
         with:
           persist-credentials: false
 
@@ -59,6 +59,6 @@ jobs:
 
       # Upload the results to GitHub's code scanning dashboard.
       - name: "Upload to code-scanning"
-        uses: github/codeql-action/upload-sarif@338146ca93283a2901a142d408241096146019b5 # v2.25.15
+        uses: github/codeql-action/upload-sarif@f0ac9bfbe331b3cc7be1482df79cca2865cb79b6 # v2.25.15
         with:
           sarif_file: results.sarif