Vulnerability · Published Aug 22, 2026 · Assigned by VulnCheck
CVE-2026-59809SiYuan before v3.8.0 Secret Exfiltration via http_request URL
Medium 4.9
In plain English
A medium-severity security flaw 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 36% of all known vulnerabilities).
Severity (CVSS 3.1)4.9Medium
Exploit odds (30 days)0.4%top 64.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| siyuan-note | siyuan | 0 – before 3.8.0 |
Weakness: CWE-201 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
References
- GitHub Security Advisory (GHSA-853m-gvvm-6rvx) vendor-advisory
- VulnCheck Advisory: SiYuan before v3.8.0 Secret Exfiltration via http_request URL third-party-advisory