GHSA-7JXJ-RPX7-PH2C

Workarounds

Add middleware to set cache headers for form uploads. Place the following code in your Startup.cs or Program.cs after app.UseStaticFiles() and any image processing middleware:

app.Use(async (context, next) =>
{
    var path = context.Request.Path.Value;

    if (!string.IsNullOrEmpty(path) && path.StartsWith("/media/forms/upload/", StringComparison.OrdinalIgnoreCase))
    {
        context.Response.OnStarting(() =>
        {
            context.Response.Headers["Cache-Control"] = "private, no-store, no-cache, must-revalidate";
            context.Response.Headers["Pragma"] = "no-cache";
            context.Response.Headers["Expires"] = "0";
            return Task.CompletedTask;
        });
    }

    await next();
});

Alternatively, configure your CDN to bypass caching for URLs matching /media/forms/upload/*.

Note: The vulnerability requires:

• A CDN in front of the website
• An authenticated user having previously requested the image
• Knowledge of the form GUID, entry GUID, and image filename

If no CDN is in use, this vulnerability does not apply.

Protected files uploaded through Umbraco Forms may be served to unauthenticated users when a CDN or caching layer is present and ImageSharp processes the request. ImageSharp sets aggressive cache headers by default, which can cause intermediary caches to store and serve files that should require authentication.

GHSA-7JXJ-RPX7-PH2C has a CVSS score of 3.1 (Low). The vector is network-reachable, no privileges required, and user interaction required. 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 (13.9.0, 16.4.0, 17.1.0); upgrading removes the vulnerable code path.

Kodem intelligence

This issue affects all (supported) versions Umbraco Forms and is patched in 13.9.0, 16.4.0 and 17.1.0.

1. What is GHSA-7JXJ-RPX7-PH2C? GHSA-7JXJ-RPX7-PH2C is a low-severity security vulnerability in Umbraco.Forms (nuget), affecting versions < 13.9.0. It is fixed in 13.9.0, 16.4.0, 17.1.0.
2. How severe is GHSA-7JXJ-RPX7-PH2C? GHSA-7JXJ-RPX7-PH2C has a CVSS score of 3.1 (Low). 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 Umbraco.Forms are affected by GHSA-7JXJ-RPX7-PH2C? Umbraco.Forms (nuget) versions < 13.9.0 is affected.
4. Is there a fix for GHSA-7JXJ-RPX7-PH2C? Yes. GHSA-7JXJ-RPX7-PH2C is fixed in 13.9.0, 16.4.0, 17.1.0. Upgrade to this version or later.
5. Is GHSA-7JXJ-RPX7-PH2C exploitable, and should I be worried? Whether GHSA-7JXJ-RPX7-PH2C 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 GHSA-7JXJ-RPX7-PH2C 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 GHSA-7JXJ-RPX7-PH2C?
   • Upgrade Umbraco.Forms to 13.9.0 or later
   • Upgrade Umbraco.Forms to 16.4.0 or later
   • Upgrade Umbraco.Forms to 17.1.0 or later

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