Vulnerability · Published Jun 16, 2026 · Assigned by VulnCheck

CVE-2026-53851OpenClaw < 2026.5.12 - Slack Reaction Event Notification Bypass

Medium 5.3

In plain English

A medium-severity missing authorization 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 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.2%top 91.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

OpenClaw before 2026.5.12 contains a notification bypass vulnerability allowing Slack reaction events to enter the agent pipeline despite disabled reaction notifications. Attackers can trigger unintended agent processing by sending reaction events when the feature is enabled, potentially leading to unauthorized processing of lower-trust input.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	openclaw	2026.5.12	GHSA-fcvx-5cxc-v5p8

Affected products (as reported)

Vendor	Product	Versions
OpenClaw	OpenClaw	0 – before 2026.5.12

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

GitHub Security Advisory (GHSA-fcvx-5cxc-v5p8) vendor-advisory
VulnCheck Advisory: OpenClaw < 2026.5.12 - Slack Reaction Event Notification Bypass third-party-advisory