{"id":"CVE-2026-6340","revision":"90684ee826754139b3f6187b5c3d5aae","records":[{"revision":"90684ee826754139b3f6187b5c3d5aae","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-6340","aliases":[],"title":"Memory Exhaustion via Malicious 7zip File Upload","description":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to validate 7zip archive structure before processing which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted 7zip file with excessive folder declarations.. Mattermost Advisory ID: MMSA-2026-00573","state":0,"publishedAt":"2026-05-18T07:08:56.863+00:00","modifiedAt":"2026-05-18T12:43:56.17+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                            \"lessThanOrEqual\": \"10.11.13\",\n                            \"status\": \"affected\",\n                            \"version\": \"10.11.0\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"lessThanOrEqual\": \"11.4.3\",\n                            \"status\": \"affected\",\n                            \"version\": \"11.4.0\",\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                            \"version\": \"10.11.14\",\n                            \"status\": \"unaffected\"\n                        },\n                        {\n                            \"version\": \"11.4.4\",\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:N/I:N/A:L","score":4.3,"severity":"MEDIUM"}],"references":["https://mattermost.com/security-updates"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-6340","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-6340","identifiers":["CVE-2026-6340"]},"retained":false,"historicalAffected":[]}],"coverage":[]}