What’s Vulnerable › Vulnerabilities
CVE-2026-33203: SiYuan has an Unauthenticated WebSocket DoS via Auth Keepalive Bypass
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2026-03-20 · updated 2026-06-17
- Weakness: CWE-248
Description
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 products
- siyuan-note siyuan: before 3.6.2 — fixed in 3.6.2
How to fix
Upgrade to a fixed version: siyuan-note siyuan 3.6.2. Check the vendor advisory for mitigations.
References
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