What is GHSA-9x8x-w6g5-hx4w?

GHSA-9x8x-w6g5-hx4w is a security advisory published by GitHub Security Advisories with Medium severity. Mattermost Server is vulnerable to XSS attacks against an OAuth 2.0 allow/deny page

Which CVE IDs does GHSA-9x8x-w6g5-hx4w cover?

GHSA-9x8x-w6g5-hx4w covers the following CVE IDs: CVE-2017-18877. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

Which products are affected by GHSA-9x8x-w6g5-hx4w?

GHSA-9x8x-w6g5-hx4w affects 3 products, including: go/github.com/mattermost/mattermost-server:\u003c 4.1.2; go/github.com/mattermost/mattermost-server:\u003e= 4.2.0, \u003c 4.2.1; go/github.com/mattermost/mattermost-server:\u003e= 4.3.0-rc1, \u003c 4.3.0.

GHSA-9x8x-w6g5-hx4wMedium

Mattermost Server is vulnerable to XSS attacks against an OAuth 2.0 allow/deny page

Vendor

GitHub Security Advisories

Published

May 24, 2022

Last Modified

December 5, 2025

🔗 CVE IDs covered (1)

CVE-2017-18877 →

📋 Description

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. XSS attacks could occur against an OAuth 2.0 allow/deny page.

🎯 Affected products3

go/github.com/mattermost/mattermost-server:< 4.1.2
go/github.com/mattermost/mattermost-server:>= 4.2.0, < 4.2.1
go/github.com/mattermost/mattermost-server:>= 4.3.0-rc1, < 4.3.0

🔗 References (3)

https://nvd.nist.gov/vuln/detail/CVE-2017-18877
https://mattermost.com/security-updates
https://github.com/advisories/GHSA-9x8x-w6g5-hx4w