CVE-2026-66395: SiYuan Desktop before v3.7.2 Reflected XSS to RCE via siyuan Protocol
SiYuan desktop before v3.7.2 contains a reflected cross-site scripting vulnerability in the bazaar plugin readme handler that allows attackers to execute arbitrary code by crafting a malicious siyuan:// deep link. Attackers can inject HTML payloads via the plugin name parameter that execute with full Node.js access through insertAdjacentHTML rendering in an insecurely configured Electron renderer.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.7.2 - Compensating control
Until upgraded, avoid opening untrusted siyuan:// deep links that could trigger the reflected XSS in the bazaar plugin readme handler.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-66395?
CVE-2026-66395 has a critical severity score of 9.6.
How do I fix CVE-2026-66395?
To fix CVE-2026-66395, update SiYuan Desktop to version 3.7.2 or later.
What type of vulnerability is CVE-2026-66395?
CVE-2026-66395 is a reflected cross-site scripting (XSS) vulnerability.
How can attackers exploit CVE-2026-66395?
Attackers can exploit CVE-2026-66395 by crafting malicious siyuan:// deep links to execute arbitrary code.
Which component of SiYuan Desktop is affected by CVE-2026-66395?
The bazaar plugin readme handler in SiYuan Desktop is affected by CVE-2026-66395.