[Bug]: Contact Search: System Address Book Avatar (Image) URL issue with IMAP

[PeteKersker]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

When searching for a system address book user using the contact search button, the user's image avatar url needs to be escaped when using UserExternal_IMAP authentication.

This is what the system generates, which does not work:
https://my.nextcloud.installation/remote.php/dav/addressbooks/system/system/system/OCA\UserExternal\IMAP:usercard.vcf?photo&size=32

Manually editing the url to escape each '\' to '%5c' does work:
https://my.nextcloud.installation/remote.php/dav/addressbooks/system/system/system/OCA%5cUserExternal%5cIMAP:usercard.vcf?photo&size=32

Steps to reproduce

1. Log in to the web interface.
2. Click on the contact search button and search for a user with a profile picture.
3. The user avatar does not appear.
   

Expected behavior

The user's avatar image should be displayed.
(Security is set correctly to allow it. The image displays correctly in the contacts app.)

Installation method

Community Manual installation with Archive

Nextcloud Server version

27

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

Web server

None

Database engine version

MariaDB

Is this bug present after an update or on a fresh install?

Upgraded to a MAJOR version (ex. 22 to 23)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "tend.agardenwalk.net"
        ],
        "overwrite.cli.url": "https:\/\/tend.agardenwalk.net",
        "htaccess.RewriteBase": "\/",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "objectstore": {
            "class": "\\OC\\Files\\ObjectStore\\S3",
            "arguments": {
                "bucket": "tend.agardenwalk.net",
                "autocreate": true,
                "key": "***REMOVED SENSITIVE VALUE***",
                "secret": "***REMOVED SENSITIVE VALUE***",
                "hostname": "s3.us-east-1.wasabisys.com",
                "region": "us-east-1",
                "port": 443,
                "use_ssl": true,
                "use_path_style": true
            }
        },
        "quota_include_external_storage": false,
        "share_folder": "\/Shared with Me",
        "dbtype": "mysql",
        "version": "27.1.4.1",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "filesystem_check_changes": 0,
        "filelocking.enabled": "true",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0,
            "dbindex": 0,
            "password": "***REMOVED SENSITIVE VALUE***",
            "timeout": 1.5
        },
        "enable_previews": true,
        "enabledPreviewProviders": [
            "OC\\Preview\\TXT",
            "OC\\Preview\\MarkDown",
            "OC\\Preview\\OpenDocument",
            "OC\\Preview\\PDF",
            "OC\\Preview\\MSOffice2003",
            "OC\\Preview\\MSOfficeDoc",
            "OC\\Preview\\Image",
            "OC\\Preview\\Photoshop",
            "OC\\Preview\\TIFF",
            "OC\\Preview\\SVG",
            "OC\\Preview\\Font",
            "OC\\Preview\\MP3",
            "OC\\Preview\\Movie",
            "OC\\Preview\\MKV",
            "OC\\Preview\\MP4",
            "OC\\Preview\\AVI"
        ],
        "remember_login_cookie_lifetime": 1296000,
        "session_lifetime": 86400,
        "session_relaxed_expiry": false,
        "session_keepalive": true,
        "auto_logout": false,
        "default_language": "en_US",
        "default_locale": "en_US",
        "default_phone_region": "en_US",
        "mail_smtpmode": "smtp",
        "mail_sendmailmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpauth": 1,
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "simpleSignUpLink.shown": false,
        "user_backends": [
            {
                "class": "\\OCA\\UserExternal\\IMAP",
                "arguments": [
                    "email.agardenwalk.net",
                    993,
                    "ssl",
                    "agardenwalk.net",
                    true,
                    true
                ]
            }
        ],
        "theme": "",
        "loglevel": 2,
        "knowledgebaseenabled": false
    }
}

List of activated Apps

Enabled:
  - activity: 2.19.0
  - analytics: 4.11.1
  - announcementcenter: 6.7.0
  - bookmarks: 13.1.1
  - bruteforcesettings: 2.7.0
  - calendar: 4.6.0
  - calendar_resource_management: 0.5.0
  - circles: 27.0.1
  - cloud_federation_api: 1.10.0
  - comments: 1.17.0
  - contacts: 5.4.2
  - contactsinteraction: 1.8.0
  - cookbook: 0.10.3
  - dashboard: 7.7.0
  - dav: 1.27.0
  - deck: 1.11.2
  - drawio: 2.1.4
  - epubviewer: 1.5.3
  - external: 5.2.1
  - federatedfilesharing: 1.17.0
  - federation: 1.17.0
  - files: 1.22.0
  - files_3dmodelviewer: 0.0.12
  - files_accesscontrol: 1.17.1
  - files_antivirus: 5.4.0
  - files_archive: 1.1.3
  - files_external: 1.19.0
  - files_markdown: 2.4.1
  - files_mindmap: 0.0.30
  - files_pdfviewer: 2.8.0
  - files_reminders: 1.0.0
  - files_rightclick: 1.6.0
  - files_sharing: 1.19.0
  - files_texteditor: 2.15.1
  - files_trashbin: 1.17.0
  - files_versions: 1.20.0
  - files_zip: 1.4.0
  - firstrunwizard: 2.16.0
  - groupfolders: 15.3.1
  - integration_peertube: 1.0.2
  - logreader: 2.12.0
  - lookup_server_connector: 1.15.0
  - mail: 3.4.5
  - maps: 1.1.1
  - music: 1.9.1
  - news: 24.0.0
  - nextcloud_announcements: 1.16.0
  - notes: 4.8.1
  - notifications: 2.15.0
  - oauth2: 1.15.1
  - oidc: 0.7.1
  - password_policy: 1.17.0
  - passwords: 2023.11.30
  - photos: 2.3.0
  - previewgenerator: 5.4.0
  - privacy: 1.11.0
  - provisioning_api: 1.17.0
  - quota_warning: 1.18.0
  - recommendations: 1.6.0
  - related_resources: 1.2.0
  - richdocuments: 8.2.3
  - serverinfo: 1.17.0
  - settings: 1.9.0
  - sharebymail: 1.17.0
  - side_menu: 3.11.2
  - sketch_picker: 1.0.1
  - spreed: 17.1.3
  - support: 1.10.0
  - survey_client: 1.15.0
  - systemtags: 1.17.0
  - tasks: 0.15.0
  - text: 3.8.0
  - theming: 2.2.0
  - theming_customcss: 1.15.0
  - twofactor_backupcodes: 1.16.0
  - updatenotification: 1.17.0
  - user_external: 3.2.0
  - user_status: 1.7.0
  - viewer: 2.1.0
  - weather_status: 1.7.0
  - welcome: 1.0.10
  - workflowengine: 2.9.0
Disabled:
  - admin_audit: 1.17.0
  - encryption: 2.15.0
  - suspicious_login: 5.0.0
  - twofactor_totp: 9.0.0
  - user_ldap: 1.17.0

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

empty

Additional info

The issue is the same in Brave, Chrome, and Firefox
Escaping the '\' in the inspector/debugger displays the image correctly.

[kesselb]

Thanks for letting us know 👍

Index: apps/dav/lib/CardDAV/AddressBookImpl.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/apps/dav/lib/CardDAV/AddressBookImpl.php b/apps/dav/lib/CardDAV/AddressBookImpl.php
--- a/apps/dav/lib/CardDAV/AddressBookImpl.php	(revision f49cff2f5af060963e6d5980d73f91a51562fa44)
+++ b/apps/dav/lib/CardDAV/AddressBookImpl.php	(date 1701895491151)
@@ -274,13 +274,14 @@
 
 		foreach ($vCard->children() as $property) {
 			if ($property->name === 'PHOTO' && in_array($property->getValueType(), ['BINARY', 'URI'])) {
+				[$userBackend, $userId] = explode(':', $uri, 2);
 				$url = $this->urlGenerator->getAbsoluteURL(
 					$this->urlGenerator->linkTo('', 'remote.php') . '/dav/');
 				$url .= implode('/', [
 					'addressbooks',
 					substr($this->addressBookInfo['principaluri'], 11), //cut off 'principals/'
 					$this->addressBookInfo['uri'],
-					$uri
+					urlencode($userBackend) . ':' . $userId,
 				]) . '?photo';
 
 				$result['PHOTO'] = 'VALUE=uri:' . $url;

The above patch may fix it.

The current code does not consider that the user backend name could contain a backslash. That's usually not the case for the integrated backends.

user_external should implement the IUserBackend to signal a proper backend name.

[PeteKersker]

Wow! Thank you for such a quick response!

Yes, it fixed the problem, but it was a breaking change. The avatars for my regular contacts ended up with a malformed url (an extra ':').

Since you pointed me to the right place, I fiddled with the code and was able to get everything to work by implementing your suggestion for the user_external code, only in this section instead.

Here's what worked:

Replace $uri
With urlencode($uri)
No other changes

I'm new to all this, so what should I do to have this change considered for a future revision?

[PeteKersker]

Update: Nextcloud 28

I upgraded to 28.0.3 and the contact photos now all come back as a circle with a ? in the middle. No url is returning at all. The patch above no longer works.

Reminder: I'm using User Authentication (IMAP) to authenticate. I'm willing to be a tester for my environment if that helps.

[PeteKersker]

Nextcloud 28.0.5 continues with the same pattern I mentioned in March. No version of the patch discussed above helps.

Please let me know if there is any way I can help.

[PeteKersker]

Update: Nextcloud 30.0.5 still an issue.

[stamepicmorg]

nextcloud 30+, same problem, official NC docker. php 8.3+.

Problem: debian\trixie have no a libc-client-dev and libc-client https://forums.debian.net/viewtopic.php?t=164351

i have extracrted 2 debs from bookworm at /usr and compilation of imap passed succesfully,

<...>
apt install -y \
        libsmbclient-dev \
        libmagickwand-dev \
        libmagickcore-dev \
        libkrb5-dev \
        libsqlite3-dev \
        libssl-dev
<...>
docker-php-ext-configure imap --with-kerberos --with-imap-ssl && \
docker-php-ext-install imap && \
docker-php-ext-enable imap 

2026-08-29 20:29:48 - INFO - [PHP Modules]
2026-08-29 20:29:48 - INFO - apcu
2026-08-29 20:29:48 - INFO - bcmath
2026-08-29 20:29:48 - INFO - bz2
2026-08-29 20:29:48 - INFO - Core
2026-08-29 20:29:48 - INFO - ctype
2026-08-29 20:29:48 - INFO - curl
2026-08-29 20:29:48 - INFO - date
2026-08-29 20:29:48 - INFO - dom
2026-08-29 20:29:48 - INFO - exif
2026-08-29 20:29:48 - INFO - fileinfo
2026-08-29 20:29:48 - INFO - filter
2026-08-29 20:29:48 - INFO - ftp
2026-08-29 20:29:48 - INFO - gd
2026-08-29 20:29:48 - INFO - gmp
2026-08-29 20:29:48 - INFO - hash
2026-08-29 20:29:48 - INFO - iconv
2026-08-29 20:29:48 - INFO - igbinary
2026-08-29 20:29:48 - INFO - imagick
2026-08-29 20:29:48 - INFO - imap
2026-08-29 20:29:48 - INFO - inotify
2026-08-29 20:29:48 - INFO - intl
2026-08-29 20:29:48 - INFO - json
2026-08-29 20:29:48 - INFO - ldap
2026-08-29 20:29:48 - INFO - libsmbclient
2026-08-29 20:29:48 - INFO - libxml
2026-08-29 20:29:48 - INFO - mbstring
2026-08-29 20:29:48 - INFO - memcached
2026-08-29 20:29:48 - INFO - mysqlnd
2026-08-29 20:29:48 - INFO - openssl
2026-08-29 20:29:48 - INFO - pcntl
2026-08-29 20:29:48 - INFO - pcre
2026-08-29 20:29:48 - INFO - PDO
2026-08-29 20:29:48 - INFO - pdo_mysql
2026-08-29 20:29:48 - INFO - pdo_pgsql
2026-08-29 20:29:48 - INFO - pdo_sqlite
2026-08-29 20:29:48 - INFO - Phar
2026-08-29 20:29:48 - INFO - posix
2026-08-29 20:29:48 - INFO - random
2026-08-29 20:29:48 - INFO - readline
2026-08-29 20:29:48 - INFO - redis
2026-08-29 20:29:48 - INFO - Reflection
2026-08-29 20:29:48 - INFO - session
2026-08-29 20:29:48 - INFO - SimpleXML
2026-08-29 20:29:48 - INFO - smbclient
2026-08-29 20:29:48 - INFO - sodium
2026-08-29 20:29:48 - INFO - SPL
2026-08-29 20:29:48 - INFO - sqlite3
2026-08-29 20:29:48 - INFO - standard
2026-08-29 20:29:48 - INFO - sysvsem
2026-08-29 20:29:48 - INFO - tokenizer
2026-08-29 20:29:48 - INFO - xml
2026-08-29 20:29:48 - INFO - xmlreader
2026-08-29 20:29:48 - INFO - xmlwriter
2026-08-29 20:29:48 - INFO - Zend OPcache
2026-08-29 20:29:48 - INFO - zip
2026-08-29 20:29:48 - INFO - zlib
2026-08-29 20:29:48 - INFO - [Zend Modules]
2026-08-29 20:29:48 - INFO - Zend OPcache
2026-08-29 20:29:48 - INFO - PHP 8.3.30 (cli) (built: Mar 16 2026 22:29:33) (NTS)
2026-08-29 20:29:48 - INFO - Copyright (c) The PHP Group
2026-08-29 20:29:48 - INFO - Zend Engine v4.3.30, Copyright (c) Zend Technologies
2026-08-29 20:29:48 - INFO -     with Zend OPcache v8.3.30, Copyright (c), by Zend Technologies

It worked by 30-32versions and php >= 8.3.

On 8.4 in future release it will not be worki think.

---

UPDATE:

for 8.4+ i changed to:

pecl channel-update pecl.php.net && \
pecl install imap && \
docker-php-ext-enable imap 

2026-08-29 21:09:02 - INFO - [PHP Modules]
2026-08-29 21:09:02 - INFO - apcu
2026-08-29 21:09:02 - INFO - bcmath
2026-08-29 21:09:02 - INFO - bz2
2026-08-29 21:09:02 - INFO - Core
2026-08-29 21:09:02 - INFO - ctype
2026-08-29 21:09:02 - INFO - curl
2026-08-29 21:09:02 - INFO - date
2026-08-29 21:09:02 - INFO - dom
2026-08-29 21:09:02 - INFO - exif
2026-08-29 21:09:02 - INFO - fileinfo
2026-08-29 21:09:02 - INFO - filter
2026-08-29 21:09:02 - INFO - ftp
2026-08-29 21:09:02 - INFO - gd
2026-08-29 21:09:02 - INFO - gmp
2026-08-29 21:09:02 - INFO - hash
2026-08-29 21:09:02 - INFO - iconv
2026-08-29 21:09:02 - INFO - igbinary
2026-08-29 21:09:02 - INFO - imagick
2026-08-29 21:09:02 - INFO - imap
2026-08-29 21:09:02 - INFO - inotify
2026-08-29 21:09:02 - INFO - intl
2026-08-29 21:09:02 - INFO - json
2026-08-29 21:09:02 - INFO - ldap
2026-08-29 21:09:02 - INFO - libsmbclient
2026-08-29 21:09:02 - INFO - libxml
2026-08-29 21:09:02 - INFO - mbstring
2026-08-29 21:09:02 - INFO - memcached
2026-08-29 21:09:02 - INFO - mysqlnd
2026-08-29 21:09:02 - INFO - openssl
2026-08-29 21:09:02 - INFO - pcntl
2026-08-29 21:09:02 - INFO - pcre
2026-08-29 21:09:02 - INFO - PDO
2026-08-29 21:09:02 - INFO - pdo_mysql
2026-08-29 21:09:02 - INFO - pdo_pgsql
2026-08-29 21:09:02 - INFO - pdo_sqlite
2026-08-29 21:09:02 - INFO - Phar
2026-08-29 21:09:02 - INFO - posix
2026-08-29 21:09:02 - INFO - random
2026-08-29 21:09:02 - INFO - readline
2026-08-29 21:09:02 - INFO - redis
2026-08-29 21:09:02 - INFO - Reflection
2026-08-29 21:09:02 - INFO - session
2026-08-29 21:09:02 - INFO - SimpleXML
2026-08-29 21:09:02 - INFO - smbclient
2026-08-29 21:09:02 - INFO - sodium
2026-08-29 21:09:02 - INFO - SPL
2026-08-29 21:09:02 - INFO - sqlite3
2026-08-29 21:09:02 - INFO - standard
2026-08-29 21:09:02 - INFO - sysvsem
2026-08-29 21:09:02 - INFO - tokenizer
2026-08-29 21:09:02 - INFO - xml
2026-08-29 21:09:02 - INFO - xmlreader
2026-08-29 21:09:02 - INFO - xmlwriter
2026-08-29 21:09:02 - INFO - Zend OPcache
2026-08-29 21:09:02 - INFO - zip
2026-08-29 21:09:02 - INFO - zlib
2026-08-29 21:09:02 - INFO - [Zend Modules]
2026-08-29 21:09:02 - INFO - Zend OPcache
2026-08-29 21:09:02 - INFO - PHP 8.4.25 (cli) (built: Aug 27 2026 20:19:28) (NTS)
2026-08-29 21:09:02 - INFO - Copyright (c) The PHP Group
2026-08-29 21:09:02 - INFO - Built by https://github.com/docker-library/php
2026-08-29 21:09:02 - INFO - Zend Engine v4.4.25, Copyright (c) Zend Technologies
2026-08-29 21:09:02 - INFO -     with Zend OPcache v8.4.25, Copyright (c), by Zend Technologies