What is GHSA-rh7p-pp3q-6cf8?

GHSA-rh7p-pp3q-6cf8 is a security advisory published by GitHub Security Advisories with Medium severity. Mattermost versions 11.10.x \u003c= 11.10.0, 11.7.x \u003c= 11.7.9, 11.9.x \u003c= 11.9.1, 11.8.x \u003c= 11.8.5 fail...

Which CVE IDs does GHSA-rh7p-pp3q-6cf8 cover?

GHSA-rh7p-pp3q-6cf8 covers the following CVE IDs: CVE-2026-18551. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-rh7p-pp3q-6cf8?

GHSA-rh7p-pp3q-6cf8 has a CVSS v3 base score of 6.5, published by GitHub Security Advisories.

GHSA-rh7p-pp3q-6cf8MediumCVSS 6.5

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail...

Vendor

GitHub Security Advisories

Published

October 16, 2026

Last Modified

October 16, 2026

🔗 CVE IDs covered (1)

CVE-2026-18551 →

📋 Description

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate the combination of guest and admin scheme roles which allows an authenticated attacker to escalate a guest account to team or channel admin via a crafted PUT request to the member roles API endpoint.. Mattermost Advisory ID: MMSA-2026-00752

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2026-18551
https://mattermost.com/security-updates
https://github.com/advisories/GHSA-rh7p-pp3q-6cf8