rickidevs/cve-2026-32913I Found a Zero-Day Vulnerability in OpenClaw — Here’s How It Went
While reviewing the source code, I focused on how OpenClaw handles HTTP requests — specifically the fetchWithSsrFGuard() function, which is responsible for making server-side fetch calls.
I noticed something off.
When a request followed a cross-origin redirect (meaning the server sent a 3xx response pointing to a different domain), OpenClaw was supposed to strip sensitive headers before forwarding the request to the new destination. It did — but only for a narrow hardcoded denylist:
Authorization, Proxy-Authorization, Cookie, Cookie2
The problem? That list is incomplete.
Custom authorization headers like X-Api-Key, Private-Token, or any other bearer-style header that developers commonly use — none of those were stripped. They were forwarded as-is to the redirect destination.
This means: if an attacker could control or influence where a redirect pointed, they could receive sensitive credentials that were never intended for them.
Imagine your application uses OpenClaw to call an internal API with a custom X-Api-Key header. A malicious server responds with a redirect to an attacker-controlled URL. OpenClaw follows the redirect — and forwards your API key right along with it.
Game over. Your credentials are now in someone else's hands.
CVSS 3.1 Score: 9.3 (Critical)
The maintainers replaced the denylist approach with a safe-header allowlist. Instead of trying to block known bad headers, the new logic only allows known safe headers through on cross-origin redirects — things like content negotiation and cache validators. Everything else gets stripped by default.
This is the correct approach. Denylist-based security is fragile; allowlist-based security is robust.
References
46715371b0612a6f9114dffd1466941ac476cef5<= 2026.3.2>= 2026.3.7Update immediately to >= 2026.3.7.
If you use custom authorization headers (like X-Api-Key or Private-Token) and you were on an older version, treat those credentials as potentially compromised and rotate them.