PT-2026-26211 · Siyuan · Siyuan

Mith36

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Published

2026-03-18

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Updated

2026-03-27

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CVE-2026-33203

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions SiYuan versions prior to 3.6.2
Description SiYuan is a personal knowledge management system. The 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. The issue resides in the kernel/server/serve.go file, specifically in the handling of the /ws?app=siyuan endpoint with the id=auth&type=auth query parameters. The vulnerable code accesses fields from the incoming JSON data using type assertions without validation, such as request["cmd"].(string), request["reqId"].(float64), and request["param"].(map[string]interface{}). Malformed or missing fields can trigger a runtime panic, leading to a denial of service.
Recommendations Versions prior to 3.6.2 should be updated to version 3.6.2 or later.

Exploit

Fix

DoS

Missing Authentication

Weakness Enumeration

Related Identifiers

CVE-2026-33203
GHSA-3G9H-9HP4-654V
GO-2026-4752
SUSE-SU-2026:1135-1

Affected Products

Siyuan