{"id":"CVE-2026-5163","revision":"d1d6b55541094083b97ac35d454705ec","records":[{"revision":"d1d6b55541094083b97ac35d454705ec","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-5163","aliases":[],"title":"Missing authorization check in AI message rewrite endpoint allows access to private thread content","description":"Mattermost versions 11.5.x <= 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite endpoint.. Mattermost Advisory ID: MMSA-2026-00645","state":0,"publishedAt":"2026-05-18T08:11:13.972+00:00","modifiedAt":"2026-05-18T14:40:03.49+00:00","affected":[{"ecosystem":"Vendor product","name":"Mattermost","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"defaultStatus\": \"unaffected\",\n                    \"product\": \"Mattermost\",\n                    \"vendor\": \"Mattermost\",\n                    \"versions\": [\n                        {\n                            \"lessThanOrEqual\": \"11.5.1\",\n                            \"status\": \"affected\",\n                            \"version\": \"11.5.0\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"11.6.0\",\n                            \"status\": \"unaffected\"\n                        },\n                        {\n                            \"version\": \"11.5.2\",\n                            \"status\": \"unaffected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","score":6.5,"severity":"MEDIUM"}],"references":["https://mattermost.com/security-updates"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-5163","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-5163","identifiers":["CVE-2026-5163"]},"retained":false,"historicalAffected":[]}],"coverage":[]}