OpenClaw < 2026.4.2 - PKCE Verifier Exposure via OAuth State Parameter

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.

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.

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.

## Summary Before OpenClaw 2026.4.2, the Gemini OAuth flow reused the PKCE verifier as the OAuth `state` value. Because the provider reflected `state` back in the redirect URL, the verifier could be exposed alongside the authorization code. ## Impact Anyone who could capture the redirect URL could learn both the authorization code and the PKCE verifier, defeating PKCE's interception protection for that flow and enabling token redemption. ## Affected Packages / Versions - Package: `openclaw` (npm) - Affected versions: `<= 2026.4.1` - Patched versions: `>= 2026.4.2` - Latest published npm version: `2026.4.1` ## Fix Commit(s) - `a26f4d0f3ef0757db6c6c40277cc06a5de76c52f` — separate OAuth state from the PKCE verifier OpenClaw thanks @BG0ECV for reporting.

### Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-9jpj-g8vv-j5mf. This link is maintained to preserve external references. ### Original Description 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.