{"id":"CVE-2026-66749","summary":"Let's Chat 0.4.0 - 0.4.8 Denial of Service via Null Dereference in Room Lookup","details":"Let's Chat 0.4.0 through 0.4.8 contains a null dereference vulnerability that allows authenticated attackers to crash the server by supplying a valid 24-character hex string room parameter that matches no document in the database. Attackers can send a crafted GET /messages request causing an uncaught TypeError in an asynchronous Mongoose callback that terminates the Node.js server process, with the same defect reachable through multiple code paths including the socket.io interface.","modified":"2026-08-12T03:51:41.310211123Z","published":"2026-07-28T15:30:46.773Z","database_specific":{"cwe_ids":["CWE-476"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66749.json","unresolved_ranges":[{"extracted_events":[{"introduced":"84981a6d2534445c00ea4e095c934e46943c0b1d"},{"last_affected":"617207ff3c0c0bf8e3c7a915bd9ec03f1dd8390c"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"VulnCheck"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66749.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66749"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/let-s-chat-denial-of-service-via-null-dereference-in-room-lookup"},{"type":"PACKAGE","url":"https://github.com/sdelements/lets-chat"},{"type":"EVIDENCE","url":"https://github.com/theopaid/Unchecked-Room-Lookup-Leads-to-Server-Crash-Let-s-Chat-"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/sdelements/lets-chat","events":[{"introduced":"ebdd712cec56da494e04f3505d10026e6f25051a"},{"last_affected":"a5e8b2d5977fedc167e1efb03a4f80121da4842e"}],"database_specific":{"extracted_events":[{"introduced":"0.4.0"},{"last_affected":"0.4.8"}],"source":"AFFECTED_FIELD"}}],"versions":["0.4.8","0.4.7","0.4.6","0.4.5","0.4.4","0.4.3","0.4.2","0.4.1","0.4.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66749.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}]}