CVE-2026-59809

medium

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.

References

https://www.vulncheck.com/advisories/siyuan-before-secret-exfiltration-via-http-request-url

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-853m-gvvm-6rvx

Details

Source: Mitre, NVD

Published: 2026-08-22

Updated: 2026-08-22

Risk Information

CVSS v2

Base Score: 6.1

Vector: CVSS2#AV:N/AC:L/Au:M/C:C/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 4.9

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

Severity: Medium

CVSS v4

Base Score: 6.9

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Severity: Medium