{"id":"CVE-2026-6957","summary":"Path traversal in Mattermost Legal Hold plugin via unsanitized file name from federated peer allows arbitrary file write.","details":"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","modified":"2026-07-08T08:14:23.960003467Z","published":"2026-05-27T14:23:50.770Z","database_specific":{"cna_assigner":"Mattermost","cwe_ids":["CWE-22"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6957.json","unresolved_ranges":[{"extracted_events":[{"last_affected":"1.1.5"}],"source":"AFFECTED_FIELD"}]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6957.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6957"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost-plugin-legal-hold","events":[{"introduced":"0"},{"last_affected":"8c830da21205c49d78929e1151384ccb10e14d97"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"last_affected":"1.1.5"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:legal_hold:*:*:*:*:*:mattermost:*:*"}}],"versions":["v1.1.5","1.1.5","v1.1.4","v1.1.3","v1.1.2","v1.1.1","v1.1.0","v1.1.0-rc1","v1.0.2","v1.0.1","v1.0.0","v0.5.0-rc1","v0.4.3","v0.4.2","v0.4.1","v0.4.0","v0.3.4","v0.3.3","v0.3.2","v0.3.1","v0.3.0","v0.2.0","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6957.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H"}]}