{"action":"Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20251212052346-61651b0df7ea or later.","affected":[{"fixed":"8.0.0-20251212052346-61651b0df7ea","introduced":"0"}],"component":"github.com/mattermost/mattermost/server/v8","cve_ids":["CVE-2026-0999"],"ecosystem":"Go","epss":0.002,"exploited":false,"fixed_versions":["8.0.0-20251212052346-61651b0df7ea"],"ghsa_id":"GHSA-3c9r-7f29-qp32","id":"tcs_01M5KGE7SJSFZBADCE9Q0444G0","modified_at":"2026-02-23T19:41:19.676979Z","published_at":"2026-02-23T18:23:12Z","references":["https://osv.dev/vulnerability/GO-2026-4520","https://github.com/advisories/GHSA-3c9r-7f29-qp32","https://nvd.nist.gov/vuln/detail/CVE-2026-0999","https://github.com/mattermost/mattermost/commit/61651b0df7ea5db55d1e54f8d6fb5fce4149309c","https://mattermost.com/security-updates"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"GO-2026-4520#Go/github.com/mattermost/mattermost/server/v8","url":"https://osv.dev/vulnerability/GO-2026-4520"}],"summary":"Mattermost fails to properly validate login method restrictions in github.com/mattermost/mattermost-server"}