Vulnerability · Published Mar 20, 2026 · Assigned by GitHub_M

CVE-2026-33203SiYuan has an Unauthenticated WebSocket DoS via Auth Keepalive Bypass

High 7.5

In plain English

A high-severity missing authentication in siyuan from siyuan-note. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.5%top 55.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/siyuan-note/siyuan/kernel	3.6.2	GHSA-3g9h-9hp4-654v
Go	github.com/siyuan-note/siyuan/kernel	no fix listed	GO-2026-4752

Affected products (as reported)

Vendor	Product	Versions
siyuan-note	siyuan	< 3.6.2

Weakness: CWE-248, CWE-306 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-3g9h-9hp4-654v x_refsource_CONFIRM