Vulnerability in Siyuan-Note Siyuan
CVE-2026-74802
SiYuan versions before 3.7.4 contain a cross-site WebSocket hijacking vulnerability in the admin-only /ws/network/proxy endpoint that explicitly disables origin validation by setting CheckOrigin to unconditionally return true. Attackers can craft malicious webpages that establish WebSocket connections to this endpoint and direct the SiYuan kernel process to proxy arbitrary network traffic to attacker-chosen targets, enabling authenticated network pivoting through the victim's machine.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (5.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
- Siyuan-Note Siyuan — versions 0, 3.7.4
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-3cc2-h3v6-rqpq (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-cross-site-websocket-hijacking-via-network-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-74802?
- CVE-2026-74802 is a high-severity vulnerability in Siyuan-Note Siyuan, classified under Origin Validation Error. CVSS score: 8.2/10. Published 2026-08-17.
- How severe is CVE-2026-74802?
- High severity. CVSS v3 base score is 8.2 out of 10.