{"action":"Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20260325191733-fb11968f8798 or later.","affected":[{"fixed":"5.3.2-0.20260325191733-fb11968f8798","introduced":"0"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2026-6340"],"ecosystem":"Go","epss":0.0024,"exploited":false,"fixed_versions":["5.3.2-0.20260325191733-fb11968f8798"],"ghsa_id":"GHSA-cjm8-jxpw-g43m","id":"tcs_01M5KF7F11RMB1B0P7QMJ7DATD","modified_at":"2026-06-25T19:56:01.421462781Z","published_at":"2026-05-18T09:31:47Z","references":["https://osv.dev/vulnerability/GHSA-cjm8-jxpw-g43m","https://nvd.nist.gov/vuln/detail/CVE-2026-6340","https://github.com/mattermost/mattermost/commit/fb11968f8798925c7b75711025bc5f991124ba26","https://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"severity":{"label":"medium","score":4.3},"sources":[{"source":"osv","source_id":"GHSA-cjm8-jxpw-g43m#Go/github.com/mattermost/mattermost-server","url":"https://osv.dev/vulnerability/GHSA-cjm8-jxpw-g43m"}],"summary":"Mattermost doesn't validate 7zip archive structure before processing"}