{"schema_version":"1.9.0","id":"GHSA-ph22-fw5m-w2q9","published":"2026-03-16T15:30:42Z","modified":"2026-03-23T18:56:18.286997Z","aliases":["CVE-2026-2457","GO-2026-4732"],"summary":"Mattermost allows attackers to spoof permalink embeds","details":"Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to sanitize client-supplied post metadata which allows an authenticated attacker to spoof permalink embeds impersonating other users via crafted PUT requests to the post update API endpoint. Mattermost Advisory ID: MMSA-2025-00569","affected":[{"package":{"name":"github.com/mattermost/mattermost/server/v8","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"8.0.0-20260123211116-9efe617be8b8"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-ph22-fw5m-w2q9/GHSA-ph22-fw5m-w2q9.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.3.2-0.20260123211116-9efe617be8b8"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-ph22-fw5m-w2q9/GHSA-ph22-fw5m-w2q9.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"10.11.0-rc1"},{"fixed":"10.11.11"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-ph22-fw5m-w2q9/GHSA-ph22-fw5m-w2q9.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.2.0-rc1"},{"fixed":"11.2.3"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-ph22-fw5m-w2q9/GHSA-ph22-fw5m-w2q9.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.3.0-rc1"},{"fixed":"11.3.1"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-ph22-fw5m-w2q9/GHSA-ph22-fw5m-w2q9.json"}}],"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-2457"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/9efe617be8b8f1d036e12721e8e73b69a543ed34"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://mattermost.com/security-updates"}],"database_specific":{"cwe_ids":["CWE-346"],"github_reviewed":true,"github_reviewed_at":"2026-03-17T20:00:12Z","nvd_published_at":"2026-03-16T14:19:29Z","severity":"MODERATE"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"}]}