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CVE-2026-42889
Published:May 12, 2026
Updated:May 18, 2026
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 Packages
https://github.com/No-Instructions/relay-server.git (GITHUB):
Affected version(s) >=debug_tool-0 <0.9.7
Fix Suggestion:
Update to version 0.9.7
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CVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Authorization Bypass Through User-Controlled Key
Incorrect Authorization