CVE-2026-23645

Name: CVE-2026-23645
Creator: NVD / NIST
Published: 2026-01-16T20:15:49.88+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.25%

Last modified Jun 17, 2026

CVE-2026-23645 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS 4.0

5.3/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.25%

16.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions	Update
B3log	Siyuan	< 3.5.4	—
B3log	Siyuan	3.5.4	Dev1

References

https://github.com/siyuan-note/siyuan/commit/11115da3d0de950593ee4ce375cf7f9018484388Patch
https://github.com/siyuan-note/siyuan/issues/16844Issue Tracking, Patch
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-pcjq-j3mq-jv5jExploit, Patch, Vendor Advisory

Timeline

Published: Jan 16, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-23645?

How severe is CVE-2026-23645?

CVE-2026-23645 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2026-23645?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-23645?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST