How severe is CVE-2024-39694?

CVE-2024-39694 has a CVSS score of 4.7/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2024-39694?

CVE-2024-39694 affects the following packages: Duende.IdentityServer (NuGet), Duende.IdentityServer (NuGet), Duende.IdentityServer (NuGet), Duende.IdentityServer (NuGet), Duende.IdentityServer (NuGet), IdentityServer4 (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2024-39694?

Update Duende.IdentityServer to 7.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-39694 is resolved across your whole dependency graph.

How do I detect CVE-2024-39694 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Duende.IdentityServer. 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-2024-39694 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-2024-39694?

O3 pinpoints whether CVE-2024-39694 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-2024-39694 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-39694 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-2024-39694?

CVE-2024-39694 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th 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-2024-39694 published, and has it been updated?

CVE-2024-39694 was published on July 31, 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-2024-39694: Duende IdentityServer Open Redirect vulnerabili…

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk39th percentile+0.36%

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

6 pkgs affected

.NETDuende.IdentityServer.NETDuende.IdentityServer.NETDuende.IdentityServer.NETDuende.IdentityServer.NETDuende.IdentityServer.NETIdentityServer4

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

Duende IdentityServer is an OpenID Connect and OAuth 2.x framework for ASP.NET Core. It is possible for an attacker to craft malicious Urls that certain functions in IdentityServer will incorrectly treat as local and trusted. If such a Url is returned as a redirect, some browsers will follow it to a third-party, untrusted site. Note: by itself, this vulnerability does not allow an attacker to obtain user credentials, authorization codes, access tokens, refresh tokens, or identity tokens. An attacker could however exploit this vulnerability as part of a phishing attack designed to steal user credentials. This vulnerability is fixed in 7.0.6, 6.3.10, 6.2.5, 6.1.8, and 6.0.5. Duende.IdentityServer 5.1 and earlier and all versions of IdentityServer4 are no longer supported and will not be receiving updates. If upgrading is not possible, use IUrlHelper.IsLocalUrl from ASP.NET Core to validate return Urls in user interface code in the IdentityServer host.

Affected Packages

6 total 5 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Duende.IdentityServer`	≥ 7.0.0-preview.1&&< 7.0.6	7.0.6
.NETNuGet	`Duende.IdentityServer`	≥ 6.3.0-preview.1&&< 6.3.10	6.3.10
.NETNuGet	`Duende.IdentityServer`	≥ 6.2.0-preview.1&&< 6.2.5	6.2.5
.NETNuGet	`Duende.IdentityServer`	≥ 6.1.0-preview.1&&< 6.1.8	6.1.8
.NETNuGet	`Duende.IdentityServer`	≥ 6.0.0-preview.1&&< 6.0.5	6.0.5
.NETNuGet	`IdentityServer4`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Duende.IdentityServer. 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 Duende.IdentityServer to 7.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-39694 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-2024-39694 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-2024-39694. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Duende IdentityServer is an OpenID Connect and OAuth 2.x framework for ASP.NET Core. It is possible for an attacker to craft malicious Urls that certain functions in IdentityServer will incorrectly treat as local and trusted. If such a Url is returned as a redirect, some browsers will follow it to a third-party, untrusted site. Note: by itself, this vulnerability does **not** allow an attacker to obtain user credentials, authorization codes, access tokens, refresh tokens, or identity tokens. An attacker could however exploit this vulnerability as part of a phishing attack designed to steal use

O3 Security · Impact-Aware SCA

Is CVE-2024-39694 in your dependencies?

O3 detects CVE-2024-39694 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-2024-39694