How severe is CVE-2026-23645?

No CVSS score has been assigned to CVE-2026-23645 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-23645?

CVE-2026-23645 affects the following packages: github.com/siyuan-note/siyuan/kernel (Go). Ecosystems affected: Go.

How do I fix CVE-2026-23645?

Update github.com/siyuan-note/siyuan/kernel to 0.0.0-20260116101155-11115da3d0de or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23645 is resolved across your whole dependency graph.

How do I detect CVE-2026-23645 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siyuan-note/siyuan/kernel, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-23645 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2026-23645 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-23645 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-23645?

CVE-2026-23645 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 21th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-23645?

CVE-2026-23645 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-23645 published, and has it been updated?

CVE-2026-23645 was published on January 16, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

CVE-2026-23645 — kernel

Fix: siyuan-note/siyuan@11115da

CVE-2026-23645 is a Cross-site Scripting (XSS) vulnerability in github.com/siyuan-note/siyuan/kernel. A fix is available for github.com/siyuan-note/siyuan/kernel — see the affected versions and patch details below.

SiYuan Vulnerable to Stored Cross-Site Scripting (XSS) via Unrestricted SVG File Upload

Also known asGHSA-pcjq-j3mq-jv5jGO-2026-4324

Published

Jan 16, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-23645.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs21th percentile — riskier than 21% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐹github.com/siyuan-note/siyuan/kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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

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" />
Create a file named test.svg with malicious JavaScript inside:

<svg xmlns="http://www.w3.org/2000/svg" width="200" height="200" viewBox="0 0 124 124" fill="none">
<rect width="124" height="124" rx="24" fill="red"/>
   <script type="text/javascript">  
      alert(window.origin);
   </script>
</svg>

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" src="https://github.com/user-attachments/assets/95c996e8-5591-436a-9467-ab56c9ffbde0" /> <img width="1321" height="548" alt="image" src="https://github.com/user-attachments/assets/249fb187-3caa-4372-a9c9-56dfda6b8a8f" /> 4. Open the file:

Right-click the uploaded asset in the note.
Select "Export" <img width="934" height="718" alt="image" src="https://github.com/user-attachments/assets/ec943dfa-92ba-47f6-8b1e-56e53f1b0ca6" />

The JavaScript code executes immediately. <img width="1033" height="632" alt="image" src="https://github.com/user-attachments/assets/a1611291-d333-4f8e-9da9-62104aaa1bdd" />

Impact

The vulnerability allows to upload an SVG file containing malicious scripts. When a user exports this file, the embedded arbitrary JavaScript code is executed within their browser context

Notes

Tested version: <img width="1440" height="534" alt="image" src="https://github.com/user-attachments/assets/a62271e4-6850-4f59-be88-c4f8055429c0" />

Solution

https://github.com/siyuan-note/siyuan/issues/16844

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/siyuan-note/siyuan/kernel`	all versions	0.0.0-20260116101155-11115da3d0de`go get github.com/siyuan-note/siyuan/kernel@v0.0.0-20260116101155-11115da3d0de`

Affected Products

1 product · 2 configurations

Application

siyuanb3log

< 3.5.4

1 version

3.5.4

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/siyuan-note/siyuan/kernel, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/siyuan-note/siyuan/kernel to 0.0.0-20260116101155-11115da3d0de or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-23645 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### 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=

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