# CVE-2026-33203

## Summary

- **CVE ID:** CVE-2026-33203
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-248, CWE-306
- **Published:** Mar 20, 2026
- **Last Modified:** Mar 23, 2026

## 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 (< 3.6.2)

## References

- [CNA](https://github.com/siyuan-note/siyuan/security/advisories/GHSA-3g9h-9hp4-654v)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.50%
- **EPSS Percentile:** 41.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._