How severe is CVE-2024-51501?

No CVSS score has been assigned to CVE-2024-51501 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2024-51501?

CVE-2024-51501 affects the following packages: Refit (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2024-51501?

Update Refit to 7.2.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-51501 is resolved across your whole dependency graph.

How do I detect CVE-2024-51501 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Refit. 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.

How do I mitigate CVE-2024-51501 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2024-51501?

O3 pinpoints whether CVE-2024-51501 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2024-51501 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-51501 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2024-51501?

CVE-2024-51501 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 41th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2024-51501 published, and has it been updated?

CVE-2024-51501 was published on November 4, 2024 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2024-51501: Refit Server-Side Request Forgery

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk41th percentile+0.43%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

.NETRefit

Real-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

Refit is an automatic type-safe REST library for .NET Core, Xamarin and .NET The various header-related Refit attributes (Header, HeaderCollection and Authorize) are vulnerable to CRLF injection. The way HTTP headers are added to a request is via the HttpHeaders.TryAddWithoutValidation method. This method does not check for CRLF characters in the header value. This means that any headers added to a refit request are vulnerable to CRLF-injection. In general, CRLF-injection into a HTTP header (when using HTTP/1.1) means that one can inject additional HTTP headers or smuggle whole HTTP requests. If an application using the Refit library passes a user-controllable value through to a header, then that application becomes vulnerable to CRLF-injection. This is not necessarily a security issue for a command line application like the one above, but if such code were present in a web application then it becomes vulnerable to request splitting (as shown in the PoC) and thus Server Side Request Forgery. Strictly speaking this is a potential vulnerability in applications using Refit and not in Refit itself. This issue has been addressed in release versions 7.2.22 and 8.0.0 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Refit`	all versions	7.2.22

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Refit. 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 Refit to 7.2.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-51501 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 CVE-2024-51501 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 CVE-2024-51501. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Refit is an automatic type-safe REST library for .NET Core, Xamarin and .NET The various header-related Refit attributes (Header, HeaderCollection and Authorize) are vulnerable to CRLF injection. The way HTTP headers are added to a request is via the `HttpHeaders.TryAddWithoutValidation` method. This method does not check for CRLF characters in the header value. This means that any headers added to a refit request are vulnerable to CRLF-injection. In general, CRLF-injection into a HTTP header (when using HTTP/1.1) means that one can inject additional HTTP headers or smuggle whole HTTP requests

O3 Security · Impact-Aware SCA

Is CVE-2024-51501 in your dependencies?

O3 detects CVE-2024-51501 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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CVE-2024-51501