{"id":"CVE-2026-42889","summary":"Relay Server WebSocket authentication bypass when token is omitted","details":"Relay adds real-time collaboration to Obsidian. Relay Server versions 0.9.0 through 0.9.6 contain an authentication bypass in the multi-document WebSocket endpoints. When authentication is configured, WebSocket connections without a token query parameter were incorrectly treated as having full server permissions. An unauthenticated network attacker who knows or guesses a document ID could connect to the document sync WebSocket and read or modify document contents without a valid document token. This vulnerability is fixed in 0.9.7.","aliases":["GHSA-9vp9-8q9j-8mqm"],"modified":"2026-08-04T11:50:20.897445303Z","published":"2026-05-12T19:30:05.552Z","database_specific":{"cwe_ids":["CWE-639","CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42889.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42889.json"},{"type":"ADVISORY","url":"https://github.com/No-Instructions/relay-server/security/advisories/GHSA-9vp9-8q9j-8mqm"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42889"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/no-instructions/relay-server","events":[{"introduced":"bc24089391fab62a67d43b9081c22faed7e2b9cd"},{"fixed":"b15b026bf8a230e12f23ad1d1b48dc0d53ce010f"}],"database_specific":{"extracted_events":[{"introduced":"0.9.0"},{"fixed":"0.9.7"}],"source":"AFFECTED_FIELD"}}],"versions":["0.9.6","0.9.5","0.9.4","0.9.3","0.9.2","0.9.1","0.9.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42889.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}