{"id":"CVE-2026-6957","aliases":["EUVD-2026-32523","GHSA-x7w4-j7hv-94wg"],"status":"published","title":"Path traversal in Mattermost Legal Hold plugin via unsanitized file name from federated peer allows arbitrary file write.","description":"Mattermost Plugins versions \u003c=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659","severity":{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00296,"percentile":0.22474,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-22"],"published":"2026-05-27T14:23:50Z","modified":"2026-10-28T02:30:21Z","products":[{"vendor":"mattermost","product":"legal_hold"},{"vendor":"mattermost","product":"mattermost"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6957","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-x7w4-j7hv-94wg"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6957.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-6957","title":"Path traversal in Mattermost Legal Hold plugin via unsanitized file name from federated peer allows arbitrary file write.","description":"Mattermost Plugins versions \u003c=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659","status":"published","published":"2026-05-27T14:23:50.77Z","modified":"2026-05-28T03:55:34.437Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T13:49:53.818886Z"}],"euvd":[{"id":"EUVD-2026-32523","description":"Mattermost Plugins versions \u003c=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659","status":"published","published":"2026-05-27T14:23:50Z","modified":"2026-05-28T03:55:34Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T18:21:03.0662Z"}],"ghsa":[{"id":"GHSA-x7w4-j7hv-94wg","title":"Mattermost Plugins versions \u003c=1.1.5 fail to sanitize filenames received from federated peers...","description":"Mattermost Plugins versions \u003c=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659","status":"published","published":"2026-05-27T15:33:28Z","modified":"2026-05-27T15:33:36Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:08:21.006908Z"}],"nvd":[{"id":"CVE-2026-6957","description":"Mattermost Plugins versions \u003c=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659","status":"published","published":"2026-05-27T15:16:34.903Z","modified":"2026-06-17T11:01:32.847Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":4.9,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:12:20.885865Z"}],"osv":[{"id":"CVE-2026-6957","title":"Path traversal in Mattermost Legal Hold plugin via unsanitized file name from federated peer allows arbitrary file write.","description":"Mattermost Plugins versions \u003c=1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via a malicious filename delivered through the shared-channel attachment sync protocol. Mattermost Advisory ID: MMSA-2026-00659","status":"published","published":"2026-05-27T14:23:50.77Z","modified":"2026-10-28T02:30:21.716412654Z","cvss":[{"version":"3.1","score":8,"vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:45:15.164658Z"}]}}