CVE-2026-82234
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.
- Published Aug 28, 2026
- CVSS 8.4 high
- 0.4% chance of exploitation in the next 30 days (EPSS)
- A fix is available