diff --git a/crates/relicario-cli/src/helpers.rs b/crates/relicario-cli/src/helpers.rs
index f794baf..5bc36a0 100644
--- a/crates/relicario-cli/src/helpers.rs
+++ b/crates/relicario-cli/src/helpers.rs
@@ -115,6 +115,21 @@ pub fn write_groups_cache(
     std::fs::write(path, body)
 }
 
+/// Sanitize a string for use in a git commit message subject line.
+///
+/// Removes all Unicode control characters (U+0000–U+001F, U+007F, and higher
+/// control planes) so that newlines and escape sequences cannot corrupt `git
+/// log` output. Truncates to 50 characters so the subject line stays within
+/// the conventional limit.
+///
+/// Audit I1: item titles are user-supplied and may contain arbitrary bytes.
+pub fn sanitize_for_commit(s: &str) -> String {
+    s.chars()
+        .filter(|c| !c.is_control())
+        .take(50)
+        .collect()
+}
+
 /// Decode a QR image at `path`. Returns the otpauth secret (base32) if the
 /// QR decodes to an `otpauth://...` URI with a `secret` query param.
 pub fn decode_totp_qr(path: &std::path::Path) -> anyhow::Result<String> {
@@ -179,6 +194,29 @@ mod tests {
         assert_eq!(iso8601(1_776_556_800), "2026-04-19T00:00:00Z");
     }
 
+    #[test]
+    fn sanitize_for_commit_strips_control_chars() {
+        assert_eq!(sanitize_for_commit("line1\nline2"), "line1line2");
+        assert_eq!(sanitize_for_commit("a\tb"), "ab");
+        assert_eq!(sanitize_for_commit("normal"), "normal");
+        assert_eq!(sanitize_for_commit("cr\r\nline"), "crline");
+        // ESC (U+001B) is control and gets stripped; bracket sequences are printable
+        assert_eq!(sanitize_for_commit("\x1b[31mred\x1b[0m"), "[31mred[0m");
+    }
+
+    #[test]
+    fn sanitize_for_commit_truncates_to_50() {
+        let long = "a".repeat(60);
+        assert_eq!(sanitize_for_commit(&long).len(), 50);
+        assert_eq!(sanitize_for_commit(&long), "a".repeat(50));
+    }
+
+    #[test]
+    fn sanitize_for_commit_allows_unicode() {
+        assert_eq!(sanitize_for_commit("cafe\u{0301}"), "cafe\u{0301}");
+        assert_eq!(sanitize_for_commit("emoji \u{1F4AA}"), "emoji \u{1F4AA}");
+    }
+
     #[test]
     fn humanize_age_buckets() {
         assert_eq!(humanize_age(0), "just now");
diff --git a/crates/relicario-cli/src/main.rs b/crates/relicario-cli/src/main.rs
index b450c54..cbe2891 100644
--- a/crates/relicario-cli/src/main.rs
+++ b/crates/relicario-cli/src/main.rs
@@ -576,7 +576,7 @@ fn cmd_add(kind: AddKind) -> Result<()> {
         paths.push(format!("attachments/{}/{}.enc", item.id.as_str(), att.id.as_str()));
     }
     let path_refs: Vec<&str> = paths.iter().map(|s| s.as_str()).collect();
-    commit_paths(&vault, &format!("add: {} ({})", item.title, item.id.as_str()), &path_refs)?;
+    commit_paths(&vault, &format!("add: {} ({})", crate::helpers::sanitize_for_commit(&item.title), item.id.as_str()), &path_refs)?;
 
     eprintln!("Added: {} (id={})", item.title, item.id.as_str());
     Ok(())
@@ -1121,7 +1121,7 @@ fn cmd_edit(query: String, totp_qr: Option<PathBuf>) -> Result<()> {
     manifest.upsert(&item);
     vault.save_manifest(&manifest)?;
     refresh_groups_cache(vault.root(), &manifest);
-    commit_paths(&vault, &format!("edit: {} ({})", item.title, item.id.as_str()),
+    commit_paths(&vault, &format!("edit: {} ({})", crate::helpers::sanitize_for_commit(&item.title), item.id.as_str()),
                  &[&format!("items/{}.enc", item.id.as_str()), "manifest.enc"])?;
     eprintln!("Updated {}", item.id.as_str());
     Ok(())
@@ -1338,7 +1338,7 @@ fn cmd_rm(query: String) -> Result<()> {
     manifest.upsert(&item);
     vault.save_manifest(&manifest)?;
     refresh_groups_cache(vault.root(), &manifest);
-    commit_paths(&vault, &format!("trash: {} ({})", item.title, item.id.as_str()),
+    commit_paths(&vault, &format!("trash: {} ({})", crate::helpers::sanitize_for_commit(&item.title), item.id.as_str()),
                  &[&format!("items/{}.enc", item.id.as_str()), "manifest.enc"])?;
     eprintln!("Moved to trash: {}", item.title);
     Ok(())
@@ -1356,7 +1356,7 @@ fn cmd_restore(query: String) -> Result<()> {
     manifest.upsert(&item);
     vault.save_manifest(&manifest)?;
     refresh_groups_cache(vault.root(), &manifest);
-    commit_paths(&vault, &format!("restore: {} ({})", item.title, item.id.as_str()),
+    commit_paths(&vault, &format!("restore: {} ({})", crate::helpers::sanitize_for_commit(&item.title), item.id.as_str()),
                  &[&format!("items/{}.enc", item.id.as_str()), "manifest.enc"])?;
     eprintln!("Restored: {}", item.title);
     Ok(())
@@ -1858,7 +1858,9 @@ fn cmd_attach(query: String, file: PathBuf) -> Result<()> {
     ];
     let path_refs: Vec<&str> = paths.iter().map(|s| s.as_str()).collect();
     commit_paths(&vault, &format!("attach: {} → {} ({})",
-                                  file.display(), item.title, item.id.as_str()), &path_refs)?;
+                                  crate::helpers::sanitize_for_commit(&file.display().to_string()),
+                                  crate::helpers::sanitize_for_commit(&item.title),
+                                  item.id.as_str()), &path_refs)?;
     eprintln!("Attached {} to {} (aid={})", file.display(), item.title, enc.id.as_str());
     Ok(())
 }
@@ -1941,7 +1943,7 @@ fn cmd_detach(query: String, aid: String) -> Result<()> {
     let blob_relpath = format!("attachments/{}/{}.enc", item.id.as_str(), removed.id.as_str());
     commit_paths(
         &vault,
-        &format!("detach: {} from {} ({})", removed.filename, item.title, item.id.as_str()),
+        &format!("detach: {} from {} ({})", crate::helpers::sanitize_for_commit(&removed.filename), crate::helpers::sanitize_for_commit(&item.title), item.id.as_str()),
         &[&item_path, "manifest.enc", &blob_relpath],
     )?;
     eprintln!("Detached {} (aid={}) from {}", removed.filename, aid, item.title);