{"action":"Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260107144005-c7f6efdfb035 or later.","affected":[{"fixed":"8.0.0-20260107144005-c7f6efdfb035","introduced":"0"}],"component":"github.com/mattermost/mattermost/server/v8","cve_ids":["CVE-2026-4265"],"ecosystem":"Go","epss":0.00232,"exploited":false,"fixed_versions":["8.0.0-20260107144005-c7f6efdfb035"],"ghsa_id":"GHSA-xpvf-6qcc-9jqc","id":"tcs_01M5KGFVYX9C5CYPNRY2WJV5HY","modified_at":"2026-03-23T18:45:18.057051Z","published_at":"2026-03-23T18:14:47Z","references":["https://osv.dev/vulnerability/GO-2026-4749","https://github.com/advisories/GHSA-xpvf-6qcc-9jqc","https://nvd.nist.gov/vuln/detail/CVE-2026-4265","https://github.com/mattermost/mattermost/commit/c7f6efdfb035490f494b3177996ee5f4b278c988","https://mattermost.com/security-updates"],"severity":{"label":"medium","score":4.3},"sources":[{"source":"osv","source_id":"GO-2026-4749#Go/github.com/mattermost/mattermost/server/v8","url":"https://osv.dev/vulnerability/GO-2026-4749"},{"source":"nvd","source_id":"CVE-2026-4265","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4265"}],"summary":"Mattermost fails to validate team-specific upload_file permissions in github.com/mattermost/mattermost-server"}