{"schema":"threatline.record/2","record":{"id":"CVE-2026-16251","aliases":[],"summary":"Mattermost local image proxy allows server memory exhaustion via unbounded image response buffering","details":"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","categories":["Applications & CMS"],"product":"Mattermost","vendor":"Mattermost","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-16251","source_modified_at":"2026-10-16T11:57:33.968Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"Mattermost","vendor":"Mattermost","versions":[{"lessThanOrEqual":"11.10.0","status":"affected","version":"11.10.0","versionType":"semver"},{"lessThanOrEqual":"11.7.9","status":"affected","version":"11.7.0","versionType":"semver"},{"lessThanOrEqual":"11.9.1","status":"affected","version":"11.9.0","versionType":"semver"},{"lessThanOrEqual":"11.8.5","status":"affected","version":"11.8.0","versionType":"semver"},{"version":"11.11.0","status":"unaffected"},{"version":"11.10.1","status":"unaffected"},{"version":"11.7.10","status":"unaffected"},{"version":"11.9.2","status":"unaffected"},{"version":"11.8.6","status":"unaffected"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":6.5,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.0028,"percentile":0.19387,"score_date":"2026-10-23"},"published_at":"2026-10-16T07:14:59.296Z","modified_at":"2026-10-16T11:57:33.968Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-16251","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-16T11:57:33.968Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-16251","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://mattermost.com/security-updates","tags":["vendor-advisory"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-16T11:29:04.337536Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-16T11:57:33.968Z","content_hash":"5946187e0f23d2a14405fb61a8cfd045c68e7b9bf4477bfb95c44b41e47674ef"}}