diff --git a/CHANGELOG.md b/CHANGELOG.md
index d1b76fe6560..5a2520bf6a5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -118,6 +118,7 @@ Docs: https://docs.openclaw.ai
 - Telegram/Outbound API proxy env: keep the Node 22 `autoSelectFamily` global-dispatcher workaround while restoring env-proxy support by using `EnvHttpProxyAgent` so `HTTP_PROXY`/`HTTPS_PROXY` continue to apply to outbound requests. (#26207) Thanks @qsysbio-cjw for reporting and @rylena and @vincentkoc for work.
 - Browser/Security: fail closed on browser-control auth bootstrap errors; if auto-auth setup fails and no explicit token/password exists, browser control server startup now aborts instead of starting unauthenticated. This ships in the next npm release. Thanks @ijxpwastaken.
 - Sandbox/noVNC hardening: increase observer password entropy, shorten observer token lifetime, and replace noVNC token redirect with a bootstrap page that keeps credentials out of `Location` query strings and adds strict no-cache/no-referrer headers.
+- Security/External content marker folding: expand Unicode angle-bracket homoglyph normalization in marker sanitization so additional guillemet, double-angle, tortoise-shell, flattened-parenthesis, and ornamental variants are folded before boundary replacement. (#30951) Thanks @benediktjohannes.
 - Docs/Slack manifest scopes: add missing DM/group-DM bot scopes (`im:read`, `im:write`, `mpim:read`, `mpim:write`) to the Slack app manifest example so DM setup guidance is complete. (#29999) Thanks @JcMinarro.
 - Slack/Onboarding token help: update setup text to include the “From manifest” app-creation path and current install wording for obtaining the `xoxb-` bot token. (#30846) Thanks @yzhong52.
 - Slack/Bot attachment-only messages: when `allowBots: true`, bot messages with empty `text` now include non-forwarded attachment `text`/`fallback` content so webhook alerts are not silently dropped. (#27616) Thanks @lailoo.
diff --git a/src/security/external-content.test.ts b/src/security/external-content.test.ts
index 6bbe5e65d86..4c573b7d3c3 100644
--- a/src/security/external-content.test.ts
+++ b/src/security/external-content.test.ts
@@ -187,6 +187,13 @@ describe("external-content security", () => {
         ["\u2039", "\u203A"], // single angle quotation marks
         ["\u27E8", "\u27E9"], // mathematical angle brackets
         ["\uFE64", "\uFE65"], // small less-than/greater-than signs
+        ["\u00AB", "\u00BB"], // guillemets (double angle quotation marks)
+        ["\u300A", "\u300B"], // CJK double angle brackets
+        ["\u27EA", "\u27EB"], // mathematical double angle brackets
+        ["\u27EC", "\u27ED"], // white tortoise shell brackets
+        ["\u27EE", "\u27EF"], // flattened parentheses
+        ["\u276C", "\u276D"], // medium angle bracket ornaments
+        ["\u276E", "\u276F"], // heavy angle quotation ornaments
       ];
 
       for (const [left, right] of bracketPairs) {
diff --git a/src/security/external-content.ts b/src/security/external-content.ts
index e1fd9335d7d..9fd4c0bc164 100644
--- a/src/security/external-content.ts
+++ b/src/security/external-content.ts
@@ -116,6 +116,20 @@ const ANGLE_BRACKET_MAP: Record<number, string> = {
   0x27e9: ">", // mathematical right angle bracket
   0xfe64: "<", // small less-than sign
   0xfe65: ">", // small greater-than sign
+  0x00ab: "<", // left-pointing double angle quotation mark
+  0x00bb: ">", // right-pointing double angle quotation mark
+  0x300a: "<", // left double angle bracket
+  0x300b: ">", // right double angle bracket
+  0x27ea: "<", // mathematical left double angle bracket
+  0x27eb: ">", // mathematical right double angle bracket
+  0x27ec: "<", // mathematical left white tortoise shell bracket
+  0x27ed: ">", // mathematical right white tortoise shell bracket
+  0x27ee: "<", // mathematical left flattened parenthesis
+  0x27ef: ">", // mathematical right flattened parenthesis
+  0x276c: "<", // medium left-pointing angle bracket ornament
+  0x276d: ">", // medium right-pointing angle bracket ornament
+  0x276e: "<", // heavy left-pointing angle quotation mark ornament
+  0x276f: ">", // heavy right-pointing angle quotation mark ornament
 };
 
 function foldMarkerChar(char: string): string {
@@ -135,7 +149,7 @@ function foldMarkerChar(char: string): string {
 
 function foldMarkerText(input: string): string {
   return input.replace(
-    /[\uFF21-\uFF3A\uFF41-\uFF5A\uFF1C\uFF1E\u2329\u232A\u3008\u3009\u2039\u203A\u27E8\u27E9\uFE64\uFE65]/g,
+    /[\uFF21-\uFF3A\uFF41-\uFF5A\uFF1C\uFF1E\u2329\u232A\u3008\u3009\u2039\u203A\u27E8\u27E9\uFE64\uFE65\u00AB\u00BB\u300A\u300B\u27EA\u27EB\u27EC\u27ED\u27EE\u27EF\u276C\u276D\u276E\u276F]/g,
     (char) => foldMarkerChar(char),
   );
 }