CVE-2026-34505

OpenClaw before 2026.3.12 applies rate limiting only after successful webhook authentication, allowing attackers to bypass rate limits and brute-force webhook secrets. Attackers can submit repeated authentication requests with invalid secrets without triggering rate limit responses, enabling systematic secret guessing and subsequent forged webhook submission.

OpenClaw before 2026.3.12 applies rate limiting only after successful webhook authentication, allowing attackers to bypass rate limits and brute-force webhook secrets. Attackers can submit repeated authentication requests with invalid secrets without triggering rate limit responses, enabling systematic secret guessing and subsequent forged webhook submission.

Summary

The Zalo webhook handler applied request rate limiting only after webhook authentication succeeded. Requests with an invalid secret returned 401 but did not count against the rate limiter, allowing repeated secret guesses without triggering 429.

Impact

This made brute-force guessing materially easier for weak but policy-compliant webhook secrets. Once the secret was guessed, an attacker could submit forged Zalo webhook traffic.

Affected versions

openclaw <= 2026.3.11

Patch

Fixed in openclaw 2026.3.12. Rate limiting now applies before successful authentication is required, closing the pre-auth brute-force gap. Users should update to 2026.3.12 or later and prefer strong webhook secrets.

OpenClaw before 2026.3.12 applies rate limiting only after successful webhook authentication, allowing attackers to bypass rate limits and brute-force webhook secrets. Attackers can submit repeated authentication requests with invalid secrets without triggering rate limit responses, enabling systematic secret guessing and subsequent forged webhook submission.

OpenClaw before 2026.3.12 applies rate limiting only after successful webhook authentication, allowing attackers to bypass rate limits and brute-force webhook secrets. Attackers can submit repeated authentication requests with invalid secrets without triggering rate limit responses, enabling systematic secret guessing and subsequent forged webhook submission.

Summary

The Zalo webhook handler applied request rate limiting only after webhook authentication succeeded. Requests with an invalid secret returned 401 but did not count against the rate limiter, allowing repeated secret guesses without triggering 429.

Impact

This made brute-force guessing materially easier for weak but policy-compliant webhook secrets. Once the secret was guessed, an attacker could submit forged Zalo webhook traffic.

Affected versions

openclaw <= 2026.3.11

Patch

Fixed in openclaw 2026.3.12. Rate limiting now applies before successful authentication is required, closing the pre-auth brute-force gap. Users should update to 2026.3.12 or later and prefer strong webhook secrets.