{"action":"No fix published. Pin and monitor.","affected":[{"introduced":"0"}],"component":"github.com/mattermost/mattermost-server/v6","cve_ids":["CVE-2026-2455"],"ecosystem":"Go","epss":0.00168,"exploited":false,"fixed_versions":[],"ghsa_id":"GHSA-gqv7-j2j8-qmwq","id":"tcs_01M5KGFTH0ZH43DWKHTPKNE0FE","modified_at":"2026-03-23T18:45:17.812647Z","published_at":"2026-03-23T18:14:47Z","references":["https://osv.dev/vulnerability/GO-2026-4746","https://github.com/advisories/GHSA-gqv7-j2j8-qmwq","https://nvd.nist.gov/vuln/detail/CVE-2026-2455","https://github.com/mattermost/mattermost/commit/5d787969c2d5ab591a9dcd61b0810475eed7a646","https://mattermost.com/security-updates"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"GO-2026-4746#Go/github.com/mattermost/mattermost-server/v6","url":"https://osv.dev/vulnerability/GO-2026-4746"}],"summary":"Mattermost fails to canonicalize IPv4-mapped IPv6 addresses before reserved IP validation in github.com/mattermost/mattermost-server"}