Summary
The Umbraco Heartcore headless client library uses a vulnerable Refit dependency package
Workarounds
If calling Refit from your own code, set any necessary HTTP headers without use of HttpHeaders.TryAddWithoutValidation.
References
See the original Refit advisory for further info.
Impact
The Heartcore headless client library depends on Refit to assist in making HTTP requests to Heartcore public APIs. Refit recently published an advisory regarding a CRLF injection vulnerability whereby it is possible for a malicious user to smuggle additional headers or potentially body content into a request.
This shouldn't affect Heartcore client library usage as the vulnerable method - HttpHeaders.TryAddWithoutValidation - is not used. However, since Refit is a transient dependency for applications using this library, then any users making direct use of Refit could be vulnerable.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The vulnerable version of Refit has been upgraded to a secure version, as of Umbraco.Headless.Client.Net version 1.5.0, available on Nuget.
Frequently Asked Questions
- What is GHSA-MGR7-5782-6JH9? GHSA-MGR7-5782-6JH9 is a low-severity security vulnerability in Umbraco.Headless.Client.Net (nuget), affecting versions <= 1.4.1. It is fixed in 1.5.0.
- Which versions of Umbraco.Headless.Client.Net are affected by GHSA-MGR7-5782-6JH9? Umbraco.Headless.Client.Net (nuget) versions <= 1.4.1 is affected.
- Is there a fix for GHSA-MGR7-5782-6JH9? Yes. GHSA-MGR7-5782-6JH9 is fixed in 1.5.0. Upgrade to this version or later.
- Is GHSA-MGR7-5782-6JH9 exploitable, and should I be worried? Whether GHSA-MGR7-5782-6JH9 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
- What actually determines whether GHSA-MGR7-5782-6JH9 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.
- How do I fix GHSA-MGR7-5782-6JH9? Upgrade
Umbraco.Headless.Client.Netto 1.5.0 or later.