{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-6957","assignerOrgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","state":"PUBLISHED","assignerShortName":"Mattermost","dateReserved":"2026-04-24T13:23:50.185Z","datePublished":"2026-05-27T14:23:50.770Z","dateUpdated":"2026-05-28T03:55:34.437Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Mattermost","vendor":"Mattermost","versions":[{"lessThanOrEqual":"1.1.5","status":"affected","version":"0","versionType":"semver"},{"version":".0","status":"unaffected"}]}],"credits":[{"lang":"en","type":"finder","value":"Hassan Mohammed"}],"descriptions":[{"lang":"en","value":"Mattermost Plugins versions <=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"}],"metrics":[{"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"HIGH","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H","baseSeverity":"HIGH","baseScore":8},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","description":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","cweId":"CWE-22"}]}],"references":[{"url":"https://mattermost.com/security-updates","name":"MMSA-2026-00659","tags":["vendor-advisory"]}],"solutions":[{"value":"Update Mattermost Plugins to versions .0 or higher.","lang":"en"}],"source":{"advisory":"MMSA-2026-00659","defect":["https://mattermost.atlassian.net/browse/MM-68411"],"discovery":"{\"self\"=>\"https://mattermost.atlassian.net/rest/api/2/customFieldOption/10557\", \"value\"=>\"Internal\", \"id\"=>\"10557\"}"},"title":"Path traversal in Mattermost Legal Hold plugin via unsanitized file name from federated peer allows arbitrary file write.","providerMetadata":{"orgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","shortName":"Mattermost","dateUpdated":"2026-05-27T14:23:50.770Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-27T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-6957"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-05-28T03:55:34.437Z"}}]}}