{"id":"GHSA-8qq9-cqj8-82w4","summary":"Mattermost doesn't sanitize FileInfo.Name received from federated peers during shared channel file sync","details":"Mattermost versions 11.6.x \u003c= 11.6.1, 11.5.x \u003c= 11.5.4, 10.11.x \u003c= 10.11.15, 10.11.x \u003c= 10.11.16 fail 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","aliases":["CVE-2026-6961","GO-2026-6281"],"modified":"2026-08-25T20:26:08.480254657Z","published":"2026-06-12T18:31:59Z","database_specific":{"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-08-24T21:45:51Z","nvd_published_at":"2026-06-12T17:16:27Z","cwe_ids":["CWE-22"]},"references":[{"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":"WEB","url":"https://mattermost.com/security-updates"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"}],"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/2026/06/GHSA-8qq9-cqj8-82w4/GHSA-8qq9-cqj8-82w4.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":"11.5.5"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 11.5.4","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-8qq9-cqj8-82w4/GHSA-8qq9-cqj8-82w4.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":"10.11.17"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-8qq9-cqj8-82w4/GHSA-8qq9-cqj8-82w4.json","last_known_affected_version_range":"\u003c= 10.11.15"}},{"package":{"name":"github.com/mattermost/mattermost/server/v8","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.0.0-20250731163400-5b955468ea1e"},{"fixed":"8.0.0-20260423180926-c021eeaff8f0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-8qq9-cqj8-82w4/GHSA-8qq9-cqj8-82w4.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L"}]}