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
Last Modified:Aug 31, 2026
EPS:Aug 28, 2026
EPSS Score:0.00321
CVSS Score:8.2
Affected Products
Vendor
Product
Action
Vendor
B3log
Product
Siyuan
B3log
Siyuan
Vendor
Siyuan
Product
Siyuan
Siyuan
Siyuan
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
