What is the CVSS score of CVE-2026-23852?

CVE-2026-23852 has a CVSS 3.1 base score of 9.6 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.2%.

Which versions of Siyuan are affected by CVE-2026-23852?

Organizations using SiYuan face critical risk from CVE-2026-23852, a code injection vulnerability rated CVSS 9.6.. A patch is available.

Is there a public PoC exploit available for CVE-2026-23852?

Yes, a public proof-of-concept exploit is available for CVE-2026-23852. Prioritise patching immediately. EPSS: 0.2%.

How to fix or mitigate CVE-2026-23852?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Validate that input sanitization is in place for all user-controlled parameters.

Siyuan CVE-2026-23852

CRITICAL

Code Injection (CWE-94)

2026-01-19 security-advisories@github.com

RCE XSS Siyuan

9.6

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

9.6 CRITICAL

AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Jan 30, 2026 - 15:08 vuln.today

Public exploit code

Patch released

Jan 30, 2026 - 15:08 nvd

Patch available

CVE Published

Jan 19, 2026 - 20:15 nvd

CRITICAL 9.6

DescriptionGitHub Advisory

SiYuan is a personal knowledge management system. Versions prior to 3.5.4 have a stored Cross-Site Scripting (XSS) vulnerability that allows an attacker to inject arbitrary HTML attributes into the icon attribute of a block via the /api/attr/setBlockAttrs API. The payload is later rendered in the dynamic icon feature in an unsanitized context, leading to stored XSS and, in the desktop environment, potential remote code execution (RCE). This issue bypasses the previous fix for issue #15970 (XSS → RCE via dynamic icons). Version 3.5.4 contains an updated fix.

AnalysisAI

SiYuan personal knowledge management system prior to 3.5.4 has a stored XSS vulnerability (CVSS 9.6) that allows code execution through crafted knowledge base entries.

Technical ContextAI

SiYuan < 3.5.4 fails to sanitize code injection payloads (CWE-94) in knowledge base entries, allowing stored XSS that executes whenever users view the malicious content. Since SiYuan is an Electron-based app, XSS can escalate to full desktop code execution.