Vulnerability in Openclaw
CVE-2026-35646
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Openclaw — versions 0, 2026.3.25
Weakness classification (CWE)
References
- github.com/openclaw/openclaw/security/advisories/GHSA-mf5g-6r6f-ghhm (vendor-advisory, Vendor Advisory, third-party-advisory)
- github.com/openclaw/openclaw/commit/0b4d07337467f4d40a0cc1ced83d45ceaec0863c (Patch, patch)
- www.vulncheck.com/advisories/openclaw-pre-authentication-rate-limit-bypass-in-w… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-35646?
- CVE-2026-35646 is a medium-severity vulnerability in Openclaw, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 4.8/10. Published 2026-04-09.
- How severe is CVE-2026-35646?
- Medium severity. CVSS v3 base score is 4.8 out of 10.