What is CVE-2024-39694?

CVE-2024-39694 is a medium-severity vulnerability in Duendesoftware Identityserver, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.7/10. Published 2024-07-31.

How severe is CVE-2024-39694?

Medium severity. CVSS v3 base score is 4.7 out of 10.

Is CVE-2024-39694 known to be exploited?

10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Open Redirect in Duendesoftware Identityserver

CVE-2024-39694

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.

Vulnerability class: Open Redirect

Published 2024-07-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.005 (42.9th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Duendesoftware Identityserver — versions < 6.0.5, >= 6.1.0-preview.1, <= 6.1.7, >= 6.2.0-preview.1, <= 6.2.4

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2024-39694?: CVE-2024-39694 is a medium-severity vulnerability in Duendesoftware Identityserver, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 4.7/10. Published 2024-07-31.
How severe is CVE-2024-39694?: Medium severity. CVSS v3 base score is 4.7 out of 10.
Is CVE-2024-39694 known to be exploited?: 10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.