CVE-2026-6957

{"id": "CVE-2026-6957", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "responsibledisclosure@mattermost.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.0, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "HIGH", "confidentialityImpact": "HIGH"}, "impactScore": 6.0, "exploitabilityScore": 1.3}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "HIGH", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.2}]}, "published": "2026-05-27T15:16:34.903", "references": [{"url": "https://mattermost.com/security-updates", "tags": ["Vendor Advisory"], "source": "responsibledisclosure@mattermost.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "responsibledisclosure@mattermost.com", "description": [{"lang": "en", "value": "CWE-22"}]}], "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"}], "lastModified": "2026-06-02T14:29:03.550", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:mattermost:legal_hold:*:*:*:*:*:mattermost:*:*", "vulnerable": true, "matchCriteriaId": "8795BB57-B7DB-4802-8A47-3DF6E6E22B2A", "versionEndIncluding": "1.1.5"}], "operator": "OR"}]}], "sourceIdentifier": "responsibledisclosure@mattermost.com"}