CVE-2026-33203CWE-248CWE-306

SiYuan has an Unauthenticated WebSocket DoS via Auth Keepalive Bypass

High · published March 20, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
47.9
In the wild
Unconfirmed
What it is

SiYuan is a personal knowledge management system. Prior to version 3.6.2, the SiYuan kernel WebSocket server accepts unauthenticated connections when a specific "auth keepalive" query parameter is present. After connection, incoming messages are parsed using unchecked type assertions on attacker-controlled JSON. A remote attacker can send malformed messages that trigger a runtime panic, potentially crashing the kernel process and causing denial of service. Version 3.6.2 fixes the issue.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00597 · 47.9th percentile
Weaknesses
CWE-248 · Uncaught Exception; CWE-306 · Missing Authentication for Critical Function
Published
2026-03-20T22:32Z
EPSS history
Timeline
  • 20 MAR 22:32Z
    SiYuan has an Unauthenticated WebSocket DoS via Auth Keepalive Bypass
    cvelistv5