{"id":"CVE-2026-66750","summary":"Let's Chat 0.3.0 - 0.4.8 Broken Access Control File Disclosure via GET /files route","details":"Let's Chat 0.3.0 through 0.4.8 contains a broken access control vulnerability that allows authenticated attackers to download file attachments from private and password-protected rooms they are not a member of by exploiting missing room membership checks in the file retrieval route. Attackers can enumerate adjacent MongoDB ObjectIds derived from a known file ID to recover files uploaded by other users, as the GET /files/:id/:name route in app/controllers/files.js only enforces login authentication without consulting room membership or the Room.canJoin check.","modified":"2026-08-01T03:32:58.794502272Z","published":"2026-07-28T15:33:04.344Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-862"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66750.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"55e8833974c83559ed2cbc12bc15febeb2466254"},{"last_affected":"617207ff3c0c0bf8e3c7a915bd9ec03f1dd8390c"}]}]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/66xxx/CVE-2026-66750.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66750"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/let-s-chat-broken-access-control-file-disclosure-via-get-files-route"},{"type":"PACKAGE","url":"https://github.com/sdelements/lets-chat"},{"type":"EVIDENCE","url":"https://github.com/theopaid/Insufficient-Access-Controls-Allow-for-Unauthorized-File-Downloads-Let-s-Chat-"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/sdelements/lets-chat","events":[{"introduced":"4795dc006f2c820bb11f3e9b5256017830f274db"},{"last_affected":"a5e8b2d5977fedc167e1efb03a4f80121da4842e"}],"database_specific":{"extracted_events":[{"introduced":"0.3.0"},{"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","0.3.6","0.3.5","0.3.4","0.3.3","0.3.2","0.3.1","0.3.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-66750.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"}]}