Go/github.com/mattermost/mattermost/server/v8 CVE-2025-12421: critical 9.9, EPSS 0.42%

Mattermost fails to to verify the token used during code exchange in github.com/mattermost/mattermost-server

Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20251022210333-acda1fb5dd46 or later.

go get github.com/mattermost/mattermost/server/v8@v8.0.0-20251022210333-acda1fb5dd46

Affected

Fixed versions

Sources

• osv: GO-2025-4170#Go/github.com/mattermost/mattermost/server/v8
• nvd: CVE-2025-12421
• https://github.com/advisories/GHSA-mp6x-97xj-9x62
• https://github.com/mattermost/mattermost/commit/5072bbf689a46b3b97b2373f26149f5891396e6b
• https://github.com/mattermost/mattermost/commit/acda1fb5dd46a2f46c76ae67012423c760525eaa
• https://github.com/mattermost/mattermost/commit/f361e7d75a7ab9df5a2106e1ceb919b94b55e41d
• https://github.com/mattermost/mattermost/commit/feb598ed2b7ac3cb78a253b032ad7e4628b0de00
• https://mattermost.com/security-updates

CVE-2025-12421 · published 2025-12-15T20:33:49Z · modified 2026-03-03T04:57:44.235626Z · JSON