VULNERABILITY INTELLIGENCE
CVE-2026-59809
CVSS score4.9 MEDIUM
EPSS probability0.41%
CISA KEVNot currently listed
Published2026-08-22
Last modified2026-10-12
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
Description
SiYuan before v3.8.0 interpolates secret placeholders into the destination URL parameter of the http_request MCP tool, allowing attackers to exfiltrate stored secrets. An MCP client can craft a request with an attacker-controlled URL containing secret placeholders to send plaintext secret values to any public host without confirmation.
Weakness classification
- disclosure@vulncheck.com: CWE-201