OpenClaw before 2026.4.2 reuses the PKCE verifier as the OAuth state parameter in the Gemini OAuth flow, exposing it through the redirect URL.
Date: 2026-04
Affected: openclaw/openclaw
Attack vector: other
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-34511
CWE: CWE-330
CVSS: 5.3 (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N)

OpenClaw before 2026.4.2 reuses the PKCE verifier as the OAuth state parameter in the Gemini OAuth flow, exposing it through the redirect URL. Attackers who capture the redirect URL can obtain both the authorization code and PKCE verifier, defeating PKCE protection and enabling token redemption.


Mitigations:

Architectural layers (MAESTRO):