CVE-2026-53837

Name: CVE-2026-53837
Creator: NVD / NIST
Published: 2026-06-12T22:16:55.567+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.3/10EPSS 0.19%

Last modified Jun 17, 2026

CVE-2026-53837 is a medium-severity vulnerability rated 6.3/10 on the CVSS scale. OpenClaw before 2026.5.6 contains an improper access control vulnerability in Mattermost event handlers that fails to validate channel type metadata. Attackers can bypass intended DM policy decisions by sending crafted Mattermost events missing channel type information to process restricted content.. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

Description

OpenClaw before 2026.5.6 contains an improper access control vulnerability in Mattermost event handlers that fails to validate channel type metadata. Attackers can bypass intended DM policy decisions by sending crafted Mattermost events missing channel type information to process restricted content.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS 4.0

6.3/10

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.19%

8.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-636

Affected Software

Vendor	Product	Versions
Openclaw	Openclaw	< 2026.5.6

References

https://github.com/openclaw/openclaw/security/advisories/GHSA-gp79-m99v-gjmhMitigation, Vendor Advisory
https://www.vulncheck.com/advisories/openclaw-missing-channel-type-validation-in-mattermost-event-handlersThird Party Advisory

Timeline

Published: Jun 12, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-53837?

How severe is CVE-2026-53837?

CVE-2026-53837 has a CVSS score of 6.3/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.

How do I fix CVE-2026-53837?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-53837?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST