CVE-2026-23645

What it is

SiYuan is self-hosted, open source personal knowledge management software. Prior to 3.5.4-dev2, a Stored Cross-Site Scripting (XSS) vulnerability exists in SiYuan Note. The application does not sanitize uploaded SVG files. If a user uploads and views a malicious SVG file (e.g., imported from an untrusted source), arbitrary JavaScript code is executed in the context of their authenticated session. This vulnerability is fixed in 3.5.4-dev2.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-01-16 20:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:21 UTC Last updatedMost recent change to the record

Details

Published

2026-01-16 20:15 UTC

Last modified

2026-06-17 10:21 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-79 · Cross-site scripting

Record status

Analyzed

Affected

• b3log Siyuan < 3.5.4
• b3log Siyuan 3.5.4

Attack profile CVSS 4.0 · 5.3

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

Passive

Confidentiality

None

Integrity

None

Availability

None