XSS in Siyuan
CVE-2026-56397
SiYuan before v3.6.1 fails to sanitize package metadata and README content in the Bazaar marketplace, allowing malicious package authors to inject arbitrary HTML and JavaScript. Attackers can achieve remote code execution on any user browsing the Bazaar by embedding XSS payloads in package displayName, description, or README fields, exploiting Electron's nodeIntegration setting to execute OS commands.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (51.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
- Siyuan — versions 0, 3.6.1
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-v3mg-9v85-fcm7 (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-remote-code-execution-via-malicious-bazaar-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-56397?
- CVE-2026-56397 is a critical-severity vulnerability in Siyuan, classified under Cross-site Scripting. CVSS score: 9.6/10. Published 2026-06-21.
- How severe is CVE-2026-56397?
- Critical severity. CVSS v3 base score is 9.6 out of 10.