{"id":"CVE-2026-6961","aliases":["GHSA-8qq9-cqj8-82w4","GO-2026-6281"],"url":"https://o3.security/vulnerability/CVE-2026-6961","summary":"CVE-2026-6961: Path traversal via unsanitized FileInfo.Name in Mattermost federation sync","details":"Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661","published":"2026-06-12T15:56:17.364Z","modified":"2026-09-29T18:26:44.594952501Z","cvss":{"score":7.6,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L"},"epss":{"score":0.00305,"percentile":0.23329,"asOf":"2026-09-17"},"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":"11.5.5"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"10.11.17"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","fixedVersion":"8.0.0-20260423180926-c021eeaff8f0"}],"fix":{"url":"https://github.com/mattermost/mattermost/pull/36255","label":"mattermost/mattermost#36255"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6961.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6961"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36255"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36253"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36252"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36251"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/pull/36223"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/c896a63dc44c2f9c081a0a15bfddc4e6eb50e753"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/c021eeaff8f003034ab40f82c552cc26a710a8fd"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/a9f3868e1eee9ec61855cd7277f39937385efffd"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/a0056ed68d95f64d7c4586985e7b7f16b96b3bec"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/61d68d2d6ee81a5919597d91c736c502d7156859"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v10.11.16"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v11.5.5"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v11.6.2"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/releases/tag/v11.7.0"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-29T18:26:44.594952501Z"}}