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Vulnerability record · CVE-2026-33203 · published 20 March 2026

CVE-2026-33203: B3log siyuan missing authentication for critical function vulnerability

B3log · Siyuan

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.

7.5 CVSS 3.1 High EPSS 0.58% · top 54.8% CWE-248 · CWE-248CWE-306 · Missing authentication for critical function
7.5CVSS 3.1 base score
0.58%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References, 1 tagged exploit
17 Jun 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2026-32767B3log siyuan sql injection vulnerabilitySiYuan is a personal knowledge management system. Versions 3.6.0 and below contain an authorization bypass vulnerability in the /api/search/fullTextS…EPSS 0.70%9.8CVE-2026-30869B3log siyuan path traversal vulnerabilitySiYuan is a personal knowledge management system. Prior to 3.5.10, a path traversal vulnerability in the /export endpoint allows an attacker to read …EPSS 1.1%9.8CVE-2024-53507B3log siyuan sql injection vulnerabilityA SQL injection vulnerability was discovered in Siyuan 3.1.11 in /getHistoryItems.EPSS 0.57%9.8CVE-2024-53504B3log siyuan sql injection vulnerabilityA SQL injection vulnerability has been identified in Siyuan 3.1.11 via the notebook parameter in /searchHistory.EPSS 0.57%9.8CVE-2024-53505B3log siyuan sql injection vulnerabilityA SQL injection vulnerability has been identified in Siyuan 3.1.11 via the id parameter at /getAssetContent.EPSS 0.51%9.8CVE-2024-53506B3log siyuan sql injection vulnerabilityA SQL injection vulnerability has been identified in Siyuan 3.1.11 via the ids array parameter in /batchGetBlockAttrs.EPSS 0.54%9.6CVE-2026-34449B3log siyuan vulnerabilitySiYuan is a personal knowledge management system. Prior to version 3.6.2, a malicious website can achieve Remote Code Execution (RCE) on any desktop …EPSS 0.80%9.1CVE-2026-32749B3log siyuan path traversal vulnerabilitySiYuan is a personal knowledge management system. In versions 3.6.0 and below, POST /api/import/importSY and POST /api/import/importZipMd write uploa…EPSS 0.57%

Source: NIST National Vulnerability Database (record CVE-2026-33203), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.