What is GHSA-27x7-qjjm-4f83?

GHSA-27x7-qjjm-4f83 is a security advisory published by GitHub Security Advisories with Medium severity. Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21, 11.8.x \u003c= 11.8.3 fail to enforce...

Which CVE IDs does GHSA-27x7-qjjm-4f83 cover?

GHSA-27x7-qjjm-4f83 covers the following CVE IDs: CVE-2026-9859. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-27x7-qjjm-4f83?

GHSA-27x7-qjjm-4f83 has a CVSS v3 base score of 6.5, published by GitHub Security Advisories.

GHSA-27x7-qjjm-4f83MediumCVSS 6.5

Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to enforce...

Vendor

GitHub Security Advisories

Published

August 18, 2026

Last Modified

August 18, 2026

🔗 CVE IDs covered (1)

CVE-2026-9859 →

📋 Description

Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to enforce PermissionManageBoardRoles on the channelId field of the batch endpoint, which allows an authenticated board editor to relink any board they can edit to an arbitrary channel via a crafted PATCH request. Mattermost Advisory ID: MMSA-2026-00686

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2026-9859
https://mattermost.com/security-updates
https://github.com/advisories/GHSA-27x7-qjjm-4f83