{"action":"Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20260113182106-a18b80ba4c32 or later.","affected":[{"fixed":"5.3.2-0.20260113182106-a18b80ba4c32","introduced":"0"},{"fixed":"10.11.11","introduced":"10.11.0-rc1"},{"fixed":"11.2.3","introduced":"11.2.0-rc1"},{"fixed":"11.3.1","introduced":"11.3.0-rc1"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2026-2458"],"ecosystem":"Go","epss":0.00168,"exploited":false,"fixed_versions":["5.3.2-0.20260113182106-a18b80ba4c32","10.11.11","11.2.3","11.3.1"],"ghsa_id":"GHSA-679f-wmrg-qf57","id":"tcs_01M5KEZHGEG14HZYYRV6V76X29","modified_at":"2026-03-23T18:56:02.455815Z","published_at":"2026-03-16T15:30:43Z","references":["https://osv.dev/vulnerability/GHSA-679f-wmrg-qf57","https://nvd.nist.gov/vuln/detail/CVE-2026-2458","https://github.com/mattermost/mattermost/commit/a18b80ba4c324b74b3d47951c33957305af4a099","https://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"severity":{"label":"medium","score":4.3},"sources":[{"source":"osv","source_id":"GHSA-679f-wmrg-qf57#Go/github.com/mattermost/mattermost-server","url":"https://osv.dev/vulnerability/GHSA-679f-wmrg-qf57"}],"summary":"Mattermost allows a removed team member to enumerate all public channels within a private team"}