Vulnerability · Published Mar 31, 2026 · Assigned by VulnCheck

CVE-2026-33580OpenClaw < 2026.3.28 - Brute Force Attack via Missing Rate Limiting on Webhook Shared Secret Authentication

Medium 6.5

In plain English

A medium-severity security flaw in OpenClaw from OpenClaw. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.4%top 68.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

OpenClaw before 2026.3.28 contains a missing rate limiting vulnerability in the Nextcloud Talk webhook authentication that allows attackers to brute-force weak shared secrets. Attackers who can reach the webhook endpoint can exploit this to forge inbound webhook events by repeatedly attempting authentication without throttling.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	openclaw	2026.3.28	GHSA-9528-x887-j2fp

Affected products (as reported)

Vendor	Product	Versions
OpenClaw	OpenClaw	0 – before 2026.3.28

Weakness: CWE-307 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-9528-x887-j2fp) vendor-advisory
Patch Commit patch
VulnCheck Advisory: OpenClaw < 2026.3.28 - Brute Force Attack via Missing Rate Limiting on Webhook Shared Secret Authentication third-party-advisory