CVE-2026-33203

SiYuan has an Unauthenticated WebSocket DoS via Auth Keepalive Bypass

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.

Affected

siyuan-note · siyuan

CVSS v3.1 GITHUB

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.60% chance of exploitation in the next 30 days, 48th percentile

Published

2026-03-20

Updated

2026-03-23

Proof-of-concept exploits (1)

• advisories/GHSA-3g9h-9hp4-654v

Security advisories

• siyuan-note/siyuan/security/advisories/GHSA-3g9h-9hp4-654v

References

• CVE Record
• NVD entry