{"action":"Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20260316171743-090408f09f53 or later.","affected":[{"fixed":"5.3.2-0.20260316171743-090408f09f53","introduced":"0"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2026-3637"],"ecosystem":"Go","epss":0.00152,"exploited":false,"fixed_versions":["5.3.2-0.20260316171743-090408f09f53"],"ghsa_id":"GHSA-v549-xx3c-6pc8","id":"tcs_01M5KFNJMFWJT2HY28XGPPKB0H","modified_at":"2026-06-25T23:11:38.862474425Z","published_at":"2026-05-18T09:31:47Z","references":["https://osv.dev/vulnerability/GHSA-v549-xx3c-6pc8","https://nvd.nist.gov/vuln/detail/CVE-2026-3637","https://github.com/mattermost/mattermost/commit/090408f09f53ffc9afc6c65c7c7c1fd3a8cd22f3","https://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"severity":{"label":"medium","score":4.3},"sources":[{"source":"osv","source_id":"GHSA-v549-xx3c-6pc8#Go/github.com/mattermost/mattermost-server","url":"https://osv.dev/vulnerability/GHSA-v549-xx3c-6pc8"}],"summary":"Mattermost doesn't check the create_post channel permission during post edit operations"}