GHSA-mgr7-5782-6jh9
The Umbraco Heartcore headless client library uses a vulnerable Refit dependency package
Blast Radius
Umbraco.Headless.Client.NetReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
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.
Patches
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.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Umbraco.Headless.Client.Net | all versions | 1.5.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Umbraco.Headless.Client.Net. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Umbraco.Headless.Client.Net to 1.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mgr7-5782-6jh9 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-mgr7-5782-6jh9 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-mgr7-5782-6jh9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-mgr7-5782-6jh9 in your dependencies?
O3 detects GHSA-mgr7-5782-6jh9 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.