OpenClaw: Gemini OAuth exposed the PKCE verifier through the OAuth state parameter

## 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.