CVE-2026-82234
SiYuan before v3.8.1 SSRF via DNS-Rebinding TOCTOU
CVSS Score
8.2
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-918 |
| Vendor | siyuan-note |
| Product | siyuan |
| Published | Aug 28, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None
Affected Versions
siyuan-note / siyuan
0 < 3.8.1
References
Credits
🔍 joysinleung