diff --git a/tooling/sanctifier-core/src/rules/mod.rs b/tooling/sanctifier-core/src/rules/mod.rs
index 8e70537..38ce3dd 100644
--- a/tooling/sanctifier-core/src/rules/mod.rs
+++ b/tooling/sanctifier-core/src/rules/mod.rs
@@ -25,6 +25,9 @@ pub mod unhandled_result;
 pub mod unsafe_prng;
 /// Unused local variables.
 pub mod unused_variable;
+/// Detect usage of env.storage().instance().update() without state check.
+pub mod storage_update_state_check;
+
 /// Variable shadowing in nested scopes.
 pub mod variable_shadowing;
 use serde::Serialize;
@@ -179,6 +182,7 @@ impl RuleRegistry {
         registry.register(unhandled_result::UnhandledResultRule::new());
         registry.register(unused_variable::UnusedVariableRule::new());
         registry.register(shadow_storage::ShadowStorageRule::new());
+        registry.register(storage_update_state_check::StorageUpdateStateCheckRule::new());
         registry.register(reentrancy::ReentrancyRule::new());
         registry.register(truncation_bounds::TruncationBoundsRule::new());
         registry.register(unsafe_prng::UnsafePrngRule::new());
diff --git a/tooling/sanctifier-core/src/rules/storage_update_state_check.rs b/tooling/sanctifier-core/src/rules/storage_update_state_check.rs
new file mode 100644
index 0000000..d44c8cf
--- /dev/null
+++ b/tooling/sanctifier-core/src/rules/storage_update_state_check.rs
@@ -0,0 +1,179 @@
+use crate::rules::{Rule, RuleViolation, Severity};
+use syn::{parse_str, File, Item, Stmt, Expr};
+use quote::ToTokens;
+
+/// Rule to detect usage of env.storage().instance().update() without a state check.
+pub struct StorageUpdateStateCheckRule;
+
+impl StorageUpdateStateCheckRule {
+    /// Creates a new instance of the rule.
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+impl Default for StorageUpdateStateCheckRule {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Rule for StorageUpdateStateCheckRule {
+    fn name(&self) -> &str {
+        "storage_update_state_check"
+    }
+
+    fn description(&self) -> &str {
+        "Detects update() without preceding state check (e.g., has()) to prevent accidental state wipes."
+    }
+
+    fn check(&self, source: &str) -> Vec<RuleViolation> {
+        let file = match parse_str::<File>(source) {
+            Ok(f) => f,
+            Err(_) => return vec![],
+        };
+
+        let mut violations = Vec::new();
+
+        for item in &file.items {
+            if let Item::Impl(impl_block) = item {
+                for impl_item in &impl_block.items {
+                    if let syn::ImplItem::Fn(fn_item) = impl_item {
+                        if let syn::Visibility::Public(_) = fn_item.vis {
+                            let fn_name = fn_item.sig.ident.to_string();
+                            if is_vulnerable_storage_update(&fn_item.block.stmts) {
+                                violations.push(RuleViolation::new(
+                                    self.name(),
+                                    Severity::Warning,
+                                    format!(
+                                        "Function '{}' calls update() without an explicit state check.",
+                                        fn_name
+                                    ),
+                                    fn_name,
+                                ).with_suggestion(
+                                    "Ensure there is a state check (e.g., env.storage().instance().has()) before calling update() to prevent accidental overwrites.".to_string()
+                                ));
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        violations
+    }
+
+    fn as_any(&self) -> &dyn std::any::Any {
+        self
+    }
+}
+
+fn is_vulnerable_storage_update(stmts: &[Stmt]) -> bool {
+    let mut has_check = false;
+
+    for stmt in stmts {
+        if check_for_state_check(stmt) {
+            has_check = true;
+        }
+
+        if check_for_vulnerable_update(stmt, has_check) {
+            return true;
+        }
+    }
+
+    false
+}
+
+fn check_for_state_check(stmt: &Stmt) -> bool {
+    match stmt {
+        Stmt::Expr(expr, _) => is_storage_has_call(expr),
+        Stmt::Local(local) => {
+            if let Some(init) = &local.init {
+                is_storage_has_call(&init.expr)
+            } else {
+                false
+            }
+        }
+        _ => false,
+    }
+}
+
+fn check_for_vulnerable_update(stmt: &Stmt, has_check: bool) -> bool {
+    match stmt {
+        Stmt::Expr(expr, _) => {
+            if is_storage_update_call(expr) {
+                return !has_check;
+            }
+            if let Expr::If(expr_if) = expr {
+                if is_storage_has_call(&expr_if.cond) {
+                    return false;
+                }
+                for s in &expr_if.then_branch.stmts {
+                    if check_for_vulnerable_update(s, has_check) {
+                        return true;
+                    }
+                }
+                if let Some((_, else_branch)) = &expr_if.else_branch {
+                    if let Expr::Block(expr_block) = else_branch.as_ref() {
+                        for s in &expr_block.block.stmts {
+                            if check_for_vulnerable_update(s, has_check) {
+                                return true;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        _ => {}
+    }
+    false
+}
+
+fn is_storage_has_call(expr: &Expr) -> bool {
+    let s = expr.to_token_stream().to_string().replace(" ", "");
+    s.contains("storage().instance().has")
+}
+
+fn is_storage_update_call(expr: &Expr) -> bool {
+    let s = expr.to_token_stream().to_string().replace(" ", "");
+    s.contains("storage().instance().update")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_storage_update_without_check() {
+        let source = r#"
+            impl MyContract {
+                pub fn vulnerable(env: Env) {
+                    env.storage().instance().update(&KEY, |old| {
+                        Ok(new_value)
+                    });
+                }
+            }
+        "#;
+        let rule = StorageUpdateStateCheckRule::new();
+        let violations = rule.check(source);
+        assert!(!violations.is_empty());
+    }
+
+    #[test]
+    fn test_storage_update_with_check() {
+        let source = r#"
+            impl MyContract {
+                pub fn safe(env: Env) {
+                    if env.storage().instance().has(&KEY) {
+                        env.storage().instance().update(&KEY, |old| {
+                            Ok(new_value)
+                        });
+                    }
+                }
+            }
+        "#;
+        let rule = StorageUpdateStateCheckRule::new();
+        let violations = rule.check(source);
+        assert!(violations.is_empty());
+    }
+}