{"schema":"threatline.record/2","record":{"id":"CVE-2026-19867","aliases":[],"summary":"Uncapped mention keys in user notification properties allow CPU exhaustion during post processing","details":"Mattermost versions 11.10.x <= 11.10.0, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to cap the number and size of mention keys stored in a user's notification properties, and to bound the quadratic multibyte-keyword matching performed for each post, which allows an authenticated user to degrade post-processing latency and consume excessive CPU on behalf of other members of any channel they share via storing an oversized notify_props.mention_keys list on their own profile.. Mattermost Advisory ID: MMSA-2026-00773","categories":["Applications & CMS"],"product":"Mattermost","vendor":"Mattermost","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-19867","source_modified_at":"2026-10-16T12:00:11.330Z","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":"11.9.1","status":"affected","version":"11.9.0","versionType":"semver"},{"lessThanOrEqual":"11.8.5","status":"affected","version":"11.8.0","versionType":"semver"},{"lessThanOrEqual":"11.7.10","status":"affected","version":"11.7.0","versionType":"semver"},{"version":"11.11.0","status":"unaffected"},{"version":"11.10.1","status":"unaffected"},{"version":"11.9.2","status":"unaffected"},{"version":"11.8.6","status":"unaffected"},{"version":"11.7.11","status":"unaffected"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":4.3,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00212,"percentile":0.10946,"score_date":"2026-10-23"},"published_at":"2026-10-16T07:00:12.550Z","modified_at":"2026-10-16T12:00:11.330Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-19867","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-16T12:00:11.330Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-19867","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":"2026-10-16T11:59:55.782423Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-16T12:00:11.330Z","content_hash":"9c493311339da18e9d9dc8e6bf54cd047222f4bc955656bfe1c84829d6d1a769"}}