# CVE-2026-116169: SiYuan stored cross-site scripting in KaTeX math blocks

Source: https://junglewise.ai/threats/cve-2026-116169-siyuan-from-2-10-0-before-3-8-7-contains-a-stored-cross-site  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-25. Updated: 2026-10-25  
License: CC BY 4.0 with a link back

CVE-2026-116169 · Severity: medium · CVSS 5.4 · Published 2026-10-25

SiYuan is a note-taking and knowledge management application. A stored cross-site scripting vulnerability in math block rendering allows users with edit permissions to inject malicious scripts that execute when other users view the document. An attacker can craft a math block containing a JavaScript URL that runs in the application's origin, potentially allowing unauthorized access to the reader's session and data.

Technologies: [SiYuan Note SiYuan](https://junglewise.ai/threats/technologies/siyuan-note-siyuan). Vendors: [SiYuan Note](https://junglewise.ai/threats/vendors/siyuan-note).

## Quick answers

**Is CVE-2026-116169 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-116169 being exploited in the wild.

**How severe is CVE-2026-116169?** Medium severity, with a CVSS score of 5.4, published 25 October 2026.

**Which products and versions are affected?** SiYuan Note SiYuan 2.10.0 before 3.8.7.

**Is there a fix for CVE-2026-116169?** Yes: fixed in v3.8.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-116169 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-116169?** Check whether you run SiYuan Note SiYuan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in v3.8.7

## Technical details

The vulnerability exists in math block rendering when KaTeX's trust mode is enabled without HTML sanitization. Attackers with edit permission can inject javascript: URLs via \href, \url, or \includegraphics LaTeX commands, which KaTeX renders as HTML attributes (href or src). The mathRender component then assigns this HTML via innerHTML, and the script executes when a reader clicks the rendered link. This requires a user click on the injected link but affects all viewers of the shared document.

## Affected products

- siyuan-note SiYuan 2.10.0 before 3.8.7

## Timeline

- 2026-10-09: disclosed
- 2026-10-25: advisory

## References

- [https://github.com/siyuan-note/siyuan/security/advisories/GHSA-hhvq-jqv9-pgjq](https://github.com/siyuan-note/siyuan/security/advisories/GHSA-hhvq-jqv9-pgjq)
- [https://www.vulncheck.com/advisories/siyuan-2.10.0-before-3.8.7-stored-xss-via-katex-href-in-math-blocks](https://www.vulncheck.com/advisories/siyuan-2.10.0-before-3.8.7-stored-xss-via-katex-href-in-math-blocks)

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