{"id":"CVE-2026-6517","summary":"Mattermost Desktop App fails to restrict the allow list of domains which NTLM credentials are passed","details":"Mattermost Desktop App versions \u003c=6.1 5.5.13.0 fail to restrict the allow list of domains to which NTLM credentials were forwarded to in the Mattermost Desktop App which allows any user on a server without the image proxy enabled to intercept other users credentials via embedding an image that routes to an external web server. Mattermost Advisory ID: MMSA-2026-00651","modified":"2026-07-15T01:49:13.989115591Z","published":"2026-06-15T13:55:25.742Z","database_specific":{"cna_assigner":"Mattermost","cwe_ids":["CWE-522"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6517.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"last_affected":"5.5.13"}]}]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6517.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6517"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/desktop","events":[{"introduced":"0"},{"last_affected":"f541b0cfdda853f51446582f7e1103c0f918a743"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"last_affected":"5.13.0"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_desktop:*:-:*:*:*:*:*:*"}}],"versions":["v5.13.0-mas.1","v5.13.0","v5.13.0-rc.1","v4.7.0-beta2","beta2","4.7.0-beta","v1.3.0-rc2","v1.3.0","v1.3.0-rc1","v1.2.0","v1.1.1","v1.1.0","v1.0.7","v1.0.6","v1.0.5","v1.0.4","v1.0.3","v1.0.2","v1.0.1","v1.0.0","v0.5.1","v0.5.0","v0.4.0","v0.3.0","v0.2.0","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6517.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N"}]}