CVE-2026-42889

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-12 20:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-26 18:10 UTC Last updatedMost recent change to the record

Details

Published

2026-05-12 20:16 UTC

Last modified

2026-10-26 18:10 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-639 · Insecure direct object reference

Record status

Deferred

Attack profile CVSS 3.1 · 9.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None