{"schema":"threatline.record/2","record":{"id":"CVE-2026-107909","aliases":[],"summary":"Pre-authentication heap out-of-bounds write in FalkorDB Bolt WebSocket frame handling via unbounded payload length","details":"A heap-based out-of-bounds write in the ws_read_frame function (src/bolt/ws.c) and the buffer_apply_mask function (src/bolt/buffer.c) in FalkorDB before 4.20.0 allows a remote unauthenticated attacker to cause a denial of service and possibly corrupt heap memory by sending a WebSocket frame with a 64-bit extended payload length to the Bolt port. The payload length is not bounded, and the only bounds check in buffer_apply_mask is an ASSERT(), which is compiled out in release builds, so the function XORs memory beyond the end of the receive buffer with the attacker-supplied mask key. Only deployments that enable the Bolt endpoint (BOLT_PORT, disabled by default) are affected.","categories":["Unclassified"],"product":"FalkorDB","vendor":"FalkorDB","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-107909","source_modified_at":"2026-10-15T15:54:47.531Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"FalkorDB","vendor":"FalkorDB","versions":[{"version":"0","lessThan":"4.20.0","status":"affected","versionType":"semver"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-107909","source_modified_at":"2026-10-15T15:54:47.531Z","fetched_at":"2026-10-23T18:48:36.087640Z","package":{"name":"FalkorDB","ecosystem":null},"version":"4.20.0","basis":"first unaffected version stated in the CVE record"}],"cvss":8.8,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00436,"percentile":0.36889,"score_date":"2026-10-23"},"published_at":"2026-10-09T05:08:12.082Z","modified_at":"2026-10-15T15:54:47.531Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-107909","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-15T15:54:47.531Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-107909","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/FalkorDB/FalkorDB/pull/2170","tags":["patch"]},{"source":"CVE List","url":"https://github.com/FalkorDB/FalkorDB/commit/0b11a00b34b25c4d4fdfe55f0a35c8a00593bd7d","tags":["patch"]},{"source":"CVE List","url":"https://github.com/FalkorDB/FalkorDB/releases/tag/v4.20.0","tags":["release-notes"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"yes","technical_impact":"total","assessed_at":"2026-10-15T15:49:07.135012Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-15T15:54:47.531Z","content_hash":"97a6bf407856eb6bd58a832534c335cf82146b4a300a7e757f3f859fd0d90c8e"}}