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

> Attackers can hijack WebSocket connections to proxy network traffic through the victim's machine, enabling network pivoting.

- **Severity:** High 7.1 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 17 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** GHSA-3cc2-h3v6-rqpq, GO-2026-6650

## What is CVE-2026-74802?

CVE-2026-74802 is a high-severity vulnerability in siyuan-note siyuan, published on 17 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-346 (Origin Validation Error)

## Which versions are affected by CVE-2026-74802?

3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260803045322-cb67e0b4fab5 |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260803045322-cb67e0b4fab5 |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260803045322-cb67e0b4fab5 |

## How do I fix CVE-2026-74802?

Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260803045322-cb67e0b4fab5 or later.

## Is CVE-2026-74802 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-74802 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74802 and fix it if it is affected.

What it is: CVE-2026-74802 is a high-severity vulnerability in siyuan-note siyuan, published on 17 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-74802 exists.

Affected packages and fixed versions:
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260803045322-cb67e0b4fab5
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260803045322-cb67e0b4fab5
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260803045322-cb67e0b4fab5

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74802/ (Markdown: https://insights.sbomify.com/CVE-2026-74802/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74802
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74802
- OSV: https://osv.dev/vulnerability/CVE-2026-74802

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74802/
Summaries are generated and may contain mistakes; the official description above is the record.