CVE-2026-82234

EUVD-2026-67686

28.08.2026, 12:16

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.

SSRF

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	8.2 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

Awaiting analysis

This vulnerability is currently awaiting analysis.

Base Score

CVSS 3.x

EPSS Score

Percentile: 24.46%

Common Weakness Enumeration

CWE-918 - Server-Side Request Forgery (SSRF)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

References

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x8gv-g2g3-65fj

https://www.vulncheck.com/advisories/siyuan-before-3.8.1-ssrf-via-dns-rebinding-toctou