CVE-2026-33203

HIGH

SiYuan has an Unauthenticated WebSocket DoS via Auth Keepalive Bypass

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 7.5
EPSS 0.0007
EPSS Percentile 20.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-248 CWE-306
Status published
Products (3)
b3log/siyuan < 3.6.2
siyuan-note/siyuan 0 - 3.6.2Go
siyuan-note/siyuan < 3.6.2
Published Mar 20, 2026
Tracked Since Mar 21, 2026