{"action":"Upgrade github.com/mattermost/mattermost-server to 10.11.11+incompatible or later.","affected":[{"fixed":"10.11.11+incompatible","introduced":"10.11.0-rc1+incompatible"},{"fixed":"11.2.3+incompatible","introduced":"11.2.0-rc1+incompatible"},{"fixed":"11.3.2+incompatible","introduced":"11.3.0-rc1+incompatible"},{"fixed":"11.4.1+incompatible","introduced":"11.4.0-rc1+incompatible"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2026-27659"],"ecosystem":"Go","epss":0.00224,"exploited":false,"fixed_versions":["10.11.11+incompatible","11.2.3+incompatible","11.3.2+incompatible","11.4.1+incompatible"],"ghsa_id":"GHSA-rmhw-c3xr-m3xx","id":"tcs_01M5KGNRJG9FFE07AFQTGJS7G4","modified_at":"2026-06-25T23:01:25.123884537Z","published_at":"2026-06-25T22:34:34Z","references":["https://osv.dev/vulnerability/GO-2026-5629","https://github.com/advisories/GHSA-rmhw-c3xr-m3xx","https://nvd.nist.gov/vuln/detail/CVE-2026-27659","https://mattermost.com/security-updates"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"GO-2026-5629","url":"https://osv.dev/vulnerability/GO-2026-5629"}],"summary":"Mattermost doesn't properly validate CSRF tokens in github.com/mattermost/mattermost-server"}