CVE-2026-55570: SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, it does not escape the untrusted fields (name, version, author, descrip...

Description

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, it does not escape the untrusted fields (name, version, author, description) when they are serialized into the data-obj HTML attribute of each marketplace card. Because the attribute is single-quoted and the value is produced with JSON.stringify() (which does not escape ', <, or >), a package whose name contains a single quote breaks out of the attribute and injects arbitrary HTML. In the desktop client the main BrowserWindow runs with nodeIntegration: true, contextIsolation: false, so the injected markup escalates from DOM XSS to arbitrary OS command execution. This is the same root cause and same impact as the original advisory, reached through a sibling sink the patch did not cover. This vulnerability is fixed in 3.7.0.

Metrics

CVSS 3.1

9/10

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

EPSS Probability

0.33%

24.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published: Jun 24, 2026
Last Modified: Jun 25, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-55570?

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, it does not escape the untrusted fields (name, version, author, description) when they are serialized into the data-obj HTML attribute of each marketplace card. Because the attribute is single-quoted and the value is produced with JSON.stringify() (which does not escape ', <, or >), a package whose name contains a single quote breaks out of the attribute and injects arbitrary HTML. In the desktop client the main BrowserWindow runs with nodeIntegration: true, contextIsolation: false, so the injected markup escalates from DOM XSS to arbitrary OS command execution. This is the same root cause and same impact as the original advisory, reached through a sibling sink the patch did not cover. This vulnerability is fixed in 3.7.0.

How severe is CVE-2026-55570?

CVE-2026-55570 has a CVSS score of 9/10 (CRITICAL severity). The EPSS model estimates a 0.33% probability of exploitation in the next 30 days.

How do I fix CVE-2026-55570?

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.