CVE-2026-42889
Relay Server WebSocket authentication bypass when token is omitted
CVSS Score
9.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-863 CWE-639 |
| Vendor | no-instructions |
| Product | relay-server |
| Published | May 12, 2026 |
| Last Updated | May 13, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
No-Instructions / relay-server
>= 0.9.0, < 0.9.7