{"id":"CVE-2026-16251","revision":"806121563eb249cfbd3bfea61c05e6f3","records":[{"revision":"806121563eb249cfbd3bfea61c05e6f3","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-16251","aliases":[],"title":"Mattermost local image proxy allows server memory exhaustion via unbounded image response buffering","description":"Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to limit the size of remote image responses buffered in memory during local image proxy direct fetches, which allows a remote attacker to cause memory exhaustion on the server via a crafted oversized image response.. Mattermost Advisory ID: MMSA-2026-00726","state":0,"publishedAt":"2026-10-16T07:14:59.296+00:00","modifiedAt":"2026-10-16T11:57:33.968+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\": \"11.10.0\",\n                            \"status\": \"affected\",\n                            \"version\": \"11.10.0\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"lessThanOrEqual\": \"11.7.9\",\n                            \"status\": \"affected\",\n                            \"version\": \"11.7.0\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"lessThanOrEqual\": \"11.9.1\",\n                            \"status\": \"affected\",\n                            \"version\": \"11.9.0\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"lessThanOrEqual\": \"11.8.5\",\n                            \"status\": \"affected\",\n                            \"version\": \"11.8.0\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"11.11.0\",\n                            \"status\": \"unaffected\"\n                        },\n                        {\n                            \"version\": \"11.10.1\",\n                            \"status\": \"unaffected\"\n                        },\n                        {\n                            \"version\": \"11.7.10\",\n                            \"status\": \"unaffected\"\n                        },\n                        {\n                            \"version\": \"11.9.2\",\n                            \"status\": \"unaffected\"\n                        },\n                        {\n                            \"version\": \"11.8.6\",\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:H","score":6.5,"severity":"MEDIUM"}],"references":["https://mattermost.com/security-updates"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-16251","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-16251","identifiers":["CVE-2026-16251"]},"retained":false,"historicalAffected":[]}],"coverage":[]}