{"schema_version":"1.7.3","id":"GHSA-9r42-rhw3-2222","published":"2026-01-16T09:31:21Z","modified":"2026-02-27T22:05:20Z","aliases":["CVE-2025-14822","GO-2026-4325"],"summary":"Mattermost is vulnerable to CPU exhaustion via crafted HTTP request","details":"Mattermost versions 10.11.x <= 10.11.8 fail to validate input size before processing hashtags which allows an authenticated attacker to exhaust CPU resources via a single HTTP request containing a post with thousands space-separated tokens.","affected":[{"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"},{"fixed":"10.11.9"}]}],"database_specific":{"last_known_affected_version_range":"<= 10.11.8","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/01/GHSA-9r42-rhw3-2222/GHSA-9r42-rhw3-2222.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.0.0"},{"fixed":"11.2.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/01/GHSA-9r42-rhw3-2222/GHSA-9r42-rhw3-2222.json"}}],"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-14822"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/4d86263f5430d0eb991fc52ec886cf778cb072e6"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/b3d6c0c564c1a79e54e5105d0a8b60fc58a2bdee"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://mattermost.com/security-updates"},{"type":"WEB","url":"https://pkg.go.dev/vuln/GO-2026-4325"}],"database_specific":{"cwe_ids":["CWE-407","CWE-770"],"github_reviewed":true,"github_reviewed_at":"2026-01-16T20:54:02Z","nvd_published_at":"2026-01-16T09:16:01Z","severity":"LOW"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L"}]}