CVE-2026-42889: 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…

PriorityP265critical9.1CVSS 3.1

AVNACLPRNUINSUCHIHAN

EPSS

0.37%

28.5th percentile

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.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
no-instructions	relay-server	—	—

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