What is GHSA-r5vf-grcx-5vqp?

GHSA-r5vf-grcx-5vqp is a security advisory published by GitHub Security Advisories with Medium severity. Mattermost versions 11.6.x \u003c= 11.6.0, 11.5.x \u003c= 11.5.3, 11.4.x \u003c= 11.4.4, 10.11.x \u003c= 10.11.14...

Which CVE IDs does GHSA-r5vf-grcx-5vqp cover?

GHSA-r5vf-grcx-5vqp covers the following CVE IDs: CVE-2026-28735. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-r5vf-grcx-5vqp?

GHSA-r5vf-grcx-5vqp has a CVSS v3 base score of 5.4, published by GitHub Security Advisories.

GHSA-r5vf-grcx-5vqpMediumCVSS 5.4

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14...

Vendor

GitHub Security Advisories

Published

May 26, 2026

Last Modified

May 26, 2026

🔗 CVE IDs covered (1)

CVE-2026-28735 →

📋 Description

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the OAuth token scope on the callback which allows an authenticated Mattermost user to gain access to private repositories via modifying the scope parameter in the GitHub authorization URL.. Mattermost Advisory ID: MMSA-2026-00628

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2026-28735
https://mattermost.com/security-updates
https://github.com/advisories/GHSA-r5vf-grcx-5vqp