{"id":"GHSA-rmvv-8v8w-rf7x","summary":"Mattermost doesn't validate user-supplied input in API request handlers","details":"Mattermost versions 11.6.x \u003c= 11.6.0, 11.5.x \u003c= 11.5.3, 11.4.x \u003c= 11.4.4, 10.11.x \u003c= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to crash the plugin process via a crafted HTTP request to the PR details endpoint. Mattermost Advisory ID: MMSA-2026-00638","aliases":["CVE-2026-4646","GO-2026-5833"],"modified":"2026-07-07T16:11:11.164972428Z","published":"2026-05-26T13:30:15Z","database_specific":{"cwe_ids":["CWE-1287"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-06-29T19:21:37Z","nvd_published_at":"2026-05-22T11:16:22Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4646"},{"type":"WEB","url":"https://github.com/mattermost/mattermost-plugin-github/commit/c2840e980b3c2bd08db656eaa6a0fe26bcbf4695"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://mattermost.com/security-updates"}],"affected":[{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.6.0"},{"fixed":"11.6.1"}]}],"versions":["11.6.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-rmvv-8v8w-rf7x/GHSA-rmvv-8v8w-rf7x.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.5.0"},{"fixed":"11.5.4"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-rmvv-8v8w-rf7x/GHSA-rmvv-8v8w-rf7x.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.4.0"},{"fixed":"11.4.5"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-rmvv-8v8w-rf7x/GHSA-rmvv-8v8w-rf7x.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"},{"fixed":"10.11.15"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-rmvv-8v8w-rf7x/GHSA-rmvv-8v8w-rf7x.json"}},{"package":{"name":"github.com/mattermost/mattermost-plugin-github","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-plugin-github"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.0.1-0.20260330164815-c2840e980b3c"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-rmvv-8v8w-rf7x/GHSA-rmvv-8v8w-rf7x.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L"}]}