CVE-2026-2454

Name: CVE-2026-2454
Creator: NVD / NIST
Published: 2026-03-16T21:16:33.89+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.6/10EPSS 0.27%

Last modified Jun 17, 2026

CVE-2026-2454 is a high-severity vulnerability rated 8.6/10 on the CVSS scale. Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to handle incorrectly reported array lengths which allows malicious user to cause OOM errors and crash the server via sending corrupted msgpack frames within websocket messages to calls plugin. Mattermost Advisory ID: MMSA-2025-00537. EPSS estimates a 0.27% chance of exploitation in the next 30 days.

Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to handle incorrectly reported array lengths which allows malicious user to cause OOM errors and crash the server via sending corrupted msgpack frames within websocket messages to calls plugin. Mattermost Advisory ID: MMSA-2025-00537

Metrics

CVSS 3.1

8.6/10

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

EPSS Probability

0.27%

19.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-1287

Affected Software

Vendor	Product	Versions
Mattermost	Mattermost Server	>= 10.11.0, < 10.11.11
Mattermost	Mattermost Server	>= 11.2.0, < 11.2.3
Mattermost	Mattermost Server	>= 11.3.0, < 11.3.1

References

https://mattermost.com/security-updatesVendor Advisory

Timeline

Published: Mar 16, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-2454?

How severe is CVE-2026-2454?

CVE-2026-2454 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.

How do I fix CVE-2026-2454?

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-2026-2454?

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

Scan your code now

Source: NVD / NIST