SiYuan Has a Stored Cross-Site Scripting (XSS) Vulnerability via Unrestricted SVG File Upload

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N · score source

EPSS

• CVE-2026-23645: 0.28% estimated exploitation activity in the next 30 days; percentile 20.53 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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. Details The application allows authenticated users to upload files, including .svg images, without sanitizing the input to remove embedded JavaScript code (such as <script tags or event handlers). PoC 1. Create a new "Daily note" in the workspace. <img width="1287" height="572" alt="image" src="https://github.com/user-attachments/assets/3a4389b9-695d-4e1b-94dc-72efdb047aa9" / 2. Create a file named test.svg with malicious JavaScript inside: 3. Upload a file in current daily note: <img width="1617" height="316" alt="image" src="https://github.com/user-attachments/assets/6e14318a-08ec-48e5-b278-9174ad17cfcb" / <img width="1482" height="739" alt="image"…

Published by the source

16 Jan 2026, 19:22 UTC

Last modified by the source

16 Jan 2026, 21:56 UTC

Source last checked

26 Oct 2026, 15:14 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-pcjq-j3mq-jv5j

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# Patch Next advisory brief: CVE-2026-23645

Advisory: SiYuan Has a Stored Cross-Site Scripting (XSS) Vulnerability via Unrestricted SVG File Upload
IDs: CVE-2026-23645, GHSA-pcjq-j3mq-jv5j
Record: https://patchnext.com/advisories/cve-2026-23645 (revision 1, source checked 26 Oct 2026, 15:14 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/siyuan-note/siyuan/kernel 0.0.0-20260116101155-11115da3d0de. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/siyuan-note/siyuan/kernel: affected < 0.0.0-20260116101155-11115da3d0de; fixed in 0.0.0-20260116101155-11115da3d0de

## Suggested inspection (read-only)
- Go github.com/siyuan-note/siyuan/kernel: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/siyuan-note/siyuan/kernel.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-pcjq-j3mq-jv5j (GitHub-reviewed advisory GHSA-pcjq-j3mq-jv5j lists affected ranges: Go github.com/siyuan-note/siyuan/kernel >=0 <0.0.0-20260116101155-11115da3d0de)

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