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.