{"action":"Upgrade github.com/mattermost/mattermost-server to 10.5.13 or later.","affected":[{"fixed":"11.0.3","introduced":"11.0.0"},{"fixed":"10.12.2","introduced":"10.12.0"},{"fixed":"10.11.5","introduced":"10.11.0"},{"fixed":"10.5.13","introduced":"10.5.0"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2025-12421"],"ecosystem":"Go","epss":0.00419,"exploited":false,"fixed_versions":["11.0.3","10.12.2","10.11.5","10.5.13"],"ghsa_id":"GHSA-mp6x-97xj-9x62","id":"tcs_01M5KFG32BY3GE0GWCV561X10M","modified_at":"2025-12-15T21:11:10.008786Z","published_at":"2025-11-27T18:30:26Z","references":["https://osv.dev/vulnerability/GHSA-mp6x-97xj-9x62","https://nvd.nist.gov/vuln/detail/CVE-2025-12421","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://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"severity":{"label":"critical","score":9.9},"sources":[{"source":"osv","source_id":"GHSA-mp6x-97xj-9x62#Go/github.com/mattermost/mattermost-server","url":"https://osv.dev/vulnerability/GHSA-mp6x-97xj-9x62"}],"summary":"Mattermost fails to to verify the token used during code exchange"}