What is GHSA-gg42-mwr6-p82c?

GHSA-gg42-mwr6-p82c is a security advisory published by GitHub Security Advisories with High severity. Mattermost Server has intermittent Authorization bypass for resource-owners

Which CVE IDs does GHSA-gg42-mwr6-p82c cover?

GHSA-gg42-mwr6-p82c covers the following CVE IDs: CVE-2017-18894. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-gg42-mwr6-p82c?

GHSA-gg42-mwr6-p82c has a CVSS v3 base score of 8.1, published by GitHub Security Advisories.

Which products are affected by GHSA-gg42-mwr6-p82c?

GHSA-gg42-mwr6-p82c affects 3 products, including: go/github.com/mattermost/mattermost-server:\u003c 4.0.5; go/github.com/mattermost/mattermost-server:\u003e= 4.1.0, \u003c 4.1.1; go/github.com/mattermost/mattermost-server:\u003e= 4.2.0-rc1, \u003c 4.2.0.

GHSA-gg42-mwr6-p82cHighCVSS 8.1

Mattermost Server has intermittent Authorization bypass for resource-owners

Vendor

GitHub Security Advisories

Published

May 24, 2022

Last Modified

January 12, 2026

🔗 CVE IDs covered (1)

CVE-2017-18894 →

📋 Description

An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5, when used as an OAuth 2.0 service provider. Resource-owner authorization can be intermittently bypassed, allowing account takeover.

🎯 Affected products3

go/github.com/mattermost/mattermost-server:< 4.0.5
go/github.com/mattermost/mattermost-server:>= 4.1.0, < 4.1.1
go/github.com/mattermost/mattermost-server:>= 4.2.0-rc1, < 4.2.0

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2017-18894
https://mattermost.com/security-updates
https://github.com/advisories/GHSA-gg42-mwr6-p82c