{"id":"CVE-2026-4646","aliases":["GHSA-rmvv-8v8w-rf7x","GO-2026-5833"],"url":"https://o3.security/vulnerability/CVE-2026-4646","summary":"Insufficient input validation in GitHub plugin API causes denial of service","details":"Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 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","published":"2026-05-22T10:25:17.315Z","modified":"2026-08-12T03:51:36.774349794Z","cvss":{"score":4.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L"},"epss":{"score":0.0025,"percentile":0.16693,"asOf":"2026-08-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"11.6.1"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"11.5.4"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"11.4.5"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"10.11.15"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-plugin-github","fixedVersion":"1.0.1-0.20260330164815-c2840e980b3c"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4646.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4646"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:36.774349794Z"}}