What is GHSA-9h79-c924-x83x?

GHSA-9h79-c924-x83x is a security advisory published by GitHub Security Advisories with Medium severity. Mattermost versions 11.10.x \u003c= 11.10.0, 11.9.x \u003c= 11.9.1, 11.8.x \u003c= 11.8.5, 11.7.x \u003c= 11.7.10...

Which CVE IDs does GHSA-9h79-c924-x83x cover?

GHSA-9h79-c924-x83x covers the following CVE IDs: CVE-2026-19867. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-9h79-c924-x83x?

GHSA-9h79-c924-x83x has a CVSS v3 base score of 4.3, published by GitHub Security Advisories.

GHSA-9h79-c924-x83xMediumCVSS 4.3

Mattermost versions 11.10.x <= 11.10.0, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10...

Vendor

GitHub Security Advisories

Published

October 16, 2026

Last Modified

October 16, 2026

🔗 CVE IDs covered (1)

CVE-2026-19867 →

📋 Description

Mattermost versions 11.10.x <= 11.10.0, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to cap the number and size of mention keys stored in a user's notification properties, and to bound the quadratic multibyte-keyword matching performed for each post, which allows an authenticated user to degrade post-processing latency and consume excessive CPU on behalf of other members of any channel they share via storing an oversized notify_props.mention_keys list on their own profile.. Mattermost Advisory ID: MMSA-2026-00773

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2026-19867
https://mattermost.com/security-updates
https://github.com/advisories/GHSA-9h79-c924-x83x