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Vulnerability record · CVE-2026-74802 · published 17 August 2026

CVE-2026-74802: Origin validation error vulnerability

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.

7.1 CVSS 4.0 High EPSS 0.16% · top 95.0% CWE-346 · Origin validation error Deferred
7.1CVSS 4.0 base score
0.16%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
3References
28 Aug 2026Last modified by NVD

Description

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.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-3cc2-h3v6-rqpq
https://www.vulncheck.com/advisories/siyuan-cross-site-websocket-hijacking-via-network-proxy
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-3cc2-h3v6-rqpq

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Source: NIST National Vulnerability Database (record CVE-2026-74802), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.