Executive brief
OpenClaw is a message processing system that integrates with Feishu (DingTalk) for bot messaging. The vulnerability allows attackers to craft malicious mention metadata that triggers either catastrophic regex backtracking (causing message processing to hang or fail) or regex injection (removing unintended message content before it reaches downstream models). This could disrupt bot operations or allow message tampering.
Technical details
The vulnerability exists in extensions/feishu/src/bot.ts within the stripBotMention() function, which constructs a RegExp object directly from untrusted Feishu mention metadata (mention.name and mention.key) without escaping regex metacharacters. This enables two attack classes: ReDoS (Regular Expression Denial of Service) via nested-quantifier patterns that trigger catastrophic backtracking, and regex injection via metacharacters that alter regex matching behavior. Both require network-accessible message input and no authentication. An attacker can send a specially crafted Feishu mention to block message processing or remove unintended content. The vulnerability was patched in version 2026.2.19; versions <= 2026.2.17 (first affected in 2026.2.6) are vulnerable.
Affected products
- OpenClaw OpenClaw <= 2026.2.17
Timeline
- 2026-02-21: disclosed
- 2026-02-19: patched: Version 2026.2.19