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.

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.

EPSS: 0.002 (15.7th percentile) — read the EPSS interpretation.

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.

Affected products

Openclaw — versions 0, 2026.3.25

Weakness classification (CWE)

CWE-307 — Improper Restriction of Excessive Authentication Attempts

References

disclosure@vulncheck.com (vendor-advisory, Vendor Advisory, third-party-advisory)
disclosure@vulncheck.com (Patch, patch)
disclosure@vulncheck.com (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.