CVE-2026-23847 SiYuan Vulnerable to Reflected Cross-Site Scripting (XSS) via /api/icon/getDynamicIcon
Attackers can execute arbitrary JavaScript in victim browsers via unsanitized SVG input in the dynamic icon API endpoint.
- 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-2026-23847?
CVE-2026-23847 is a low-severity cross-site scripting vulnerability in B3log Siyuan, published on 19 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 a personal knowledge management system. Versions prior to 3.5.4 are vulnerable to reflected cross-site scripting in /api/icon/getDynamicIcon due to unsanitized SVG input. The endpoint generates SVG images for text icons (type=8). The content query parameter is inserted directly into the SVG <text> tag without XML escaping. Since the response Content-Type is image/svg+xml, injecting unescaped tags allows breaking the XML structure and executing JavaScript. Version 3.5.4 patches the issue.]
Weakness: CWE-79
Which versions are affected by CVE-2026-23847?
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 | 0.0.0-20260118021606-5c0cc375b475 |
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260118021606-5c0cc375b475 |
github.com/siyuan-note/siyuan/kernel Go | All versions | 0.0.0-20260118021606-5c0cc375b475 |
Products include B3log Siyuan.
How do I fix CVE-2026-23847?
Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260118021606-5c0cc375b475 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-2026-23847 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-23847 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-w836-5gpm-7r93, GO-2026-4343.