CVE-2026-23645 SiYuan Vulnerable to Stored Cross-Site Scripting (XSS) via Unrestricted SVG File Upload
Attackers can execute arbitrary JavaScript in a victim's session by uploading malicious SVG files to SiYuan, potentially leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-23645?
CVE-2026-23645 is a medium-severity cross-site scripting vulnerability in B3log Siyuan, published on 16 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-23645?
3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260116101155-11115da3d0de |
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260116101155-11115da3d0de |
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260116101155-11115da3d0de |
Products include B3log Siyuan.
How do I fix CVE-2026-23645?
Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260116101155-11115da3d0de or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-23645 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-23645 exists.
Other vulnerabilities in B3log Siyuan
- CVE-2026-32938 SiYuan has an Arbitrary File Read in its Desktop Publish Service
- CVE-2026-33669 SiYuan has Arbitrary Document Reading within the Publishing Service
- CVE-2026-33670 SiYuan has directory traversal within its publishing service
- CVE-2026-32767 SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API
- CVE-2024-53504 SQL injection in n/a
Sources
Also known as GHSA-pcjq-j3mq-jv5j, GO-2026-4324.