CVE-2026-82234: Siyuan-Note Siyuan

High severity, CVSS 8.2. EPSS: 0.4% chance of exploitation in the next 30 days.

SiYuan versions before v3.8.1 contain a server-side request forgery vulnerability in the http_request and web_fetch agent tools that perform DNS resolution only at guard time without validating the connect-time resolution. Attackers can use DNS rebinding to answer the guard resolution with a public IP and the connect resolution with a private or metadata IP, bypassing the SSRF defense to access cloud instance metadata and internal services.

Affected products

• Siyuan-Note Siyuan: before 3.8.1 (fixed in 3.8.1)

Published 2026-08-28. Last modified 2026-08-28.