{"id":"CVE-2026-42889","aliases":["EUVD-2026-29792","GHSA-9vp9-8q9j-8mqm"],"status":"published","title":"Relay Server WebSocket authentication bypass when token is omitted","description":"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.","severity":{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00366,"percentile":0.30872,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-639","CWE-863"],"published":"2026-05-12T19:30:05Z","modified":"2026-10-28T02:31:13Z","products":[{"vendor":"no-instructions","product":"relay-server"}],"references":[{"url":"https://github.com/No-Instructions/relay-server/security/advisories/GHSA-9vp9-8q9j-8mqm","tags":["x_refsource_CONFIRM","exploit","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42889.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42889","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-42889","title":"Relay Server WebSocket authentication bypass when token is omitted","description":"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.","status":"published","published":"2026-05-12T19:30:05.552Z","modified":"2026-05-13T12:32:58.746Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"cna"}],"cwes":["CWE-863","CWE-639"],"updated_at":"2026-11-02T13:40:23.731501Z"}],"euvd":[{"id":"EUVD-2026-29792","description":"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.","status":"published","published":"2026-05-12T19:30:05Z","modified":"2026-05-13T12:32:58Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical"}],"updated_at":"2026-11-02T19:04:34.274348Z"}],"nvd":[{"id":"CVE-2026-42889","description":"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.","status":"published","published":"2026-05-12T20:16:42.143Z","modified":"2026-10-26T18:10:00.173Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"secondary"}],"cwes":["CWE-639","CWE-863"],"updated_at":"2026-11-02T14:12:18.613259Z"}],"osv":[{"id":"CVE-2026-42889","title":"Relay Server WebSocket authentication bypass when token is omitted","description":"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.","status":"published","published":"2026-05-12T19:30:05.552Z","modified":"2026-10-28T02:31:13.729794527Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical"}],"cwes":["CWE-639","CWE-863"],"updated_at":"2026-11-02T15:45:04.117819Z"}]}}