What is GHSA-cjm8-jxpw-g43m?

GHSA-cjm8-jxpw-g43m is a security advisory published by GitHub Security Advisories with Medium severity. Mattermost versions 11.5.x \u003c= 11.5.1, 10.11.x \u003c= 10.11.13, 11.4.x \u003c= 11.4.3 fail to validate 7zip...

Which CVE IDs does GHSA-cjm8-jxpw-g43m cover?

GHSA-cjm8-jxpw-g43m covers the following CVE IDs: CVE-2026-6340. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-cjm8-jxpw-g43m?

GHSA-cjm8-jxpw-g43m has a CVSS v3 base score of 4.3, published by GitHub Security Advisories.

GHSA-cjm8-jxpw-g43mMediumCVSS 4.3

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate 7zip...

Vendor

GitHub Security Advisories

Published

May 18, 2026

Last Modified

May 18, 2026

🔗 CVE IDs covered (1)

CVE-2026-6340 →

📋 Description

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate 7zip archive structure before processing which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted 7zip file with excessive folder declarations.. Mattermost Advisory ID: MMSA-2026-00573

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2026-6340
https://mattermost.com/security-updates
https://github.com/advisories/GHSA-cjm8-jxpw-g43m