Vulnerability · Published Aug 28, 2026 · Assigned by VulnCheck

CVE-2026-82234SiYuan before v3.8.1 SSRF via DNS-Rebinding TOCTOU

High 8.2

In plain English

A high-severity server-side request forgery in siyuan from siyuan-note. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.4%top 69.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/siyuan-note/siyuan/kernel	0.0.0-20260813142806-dd2778b70d02	GHSA-x8gv-g2g3-65fj
Go	github.com/siyuan-note/siyuan/kernel	0.0.0-20260813142806-dd2778b70d02	GO-2026-6657

Affected products (as reported)

Vendor	Product	Versions
siyuan-note	siyuan	0 – before 3.8.1

Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

References

GitHub Security Advisory (GHSA-x8gv-g2g3-65fj) vendor-advisory
VulnCheck Advisory: SiYuan before v3.8.1 SSRF via DNS-Rebinding TOCTOU third-party-advisory