How severe is GHSA-55p7-v223-x366?

GHSA-55p7-v223-x366 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 GHSA-55p7-v223-x366?

GHSA-55p7-v223-x366 affects the following packages: IdentityServer4 (NuGet). Ecosystems affected: NuGet.

How do I fix GHSA-55p7-v223-x366?

No patched version of IdentityServer4 has shipped for GHSA-55p7-v223-x366 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect GHSA-55p7-v223-x366 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for IdentityServer4, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-55p7-v223-x366 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 GHSA-55p7-v223-x366?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-55p7-v223-x366 can be triaged on real exposure rather than presence alone.

Is GHSA-55p7-v223-x366 actively exploited in the wild?

No public exploit code has been indexed for GHSA-55p7-v223-x366 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.

When was GHSA-55p7-v223-x366 published, and has it been updated?

GHSA-55p7-v223-x366 was published on July 31, 2024 and was last updated on November 30, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET

.NET NuGet

Not in CISA KEV

MEDIUM severity

GHSA-55p7-v223-x366 — IdentityServer4

MEDIUM

GHSA-55p7-v223-x366 is a medium-severity (CVSS 4.7) vulnerability in IdentityServer4. No vendor fix is recorded yet; mitigation options are listed below.

IdentityServer Open Redirect vulnerability

Published

Jul 31, 2024

Updated

Nov 30, 2024

Affected

1 pkg

Patched

None yet

Exploits

None indexed

Exploitation data as of Nov 30, 2024 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

.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

Impact

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.

Affected Methods

In the DefaultIdentityServerInteractionService, the GetAuthorizationContextAsync method may return non-null and the IsValidReturnUrl method may return true for malicious Urls, indicating incorrectly that they can be safely redirected to.

UI code calling these two methods is the most commonly used code path that will expose the vulnerability. The default UI templates rely on this behavior in the Login, Challenge, and Consent pages. Customized user interface code might also rely on this behavior. The following uncommonly used APIs are also vulnerable:
The ServerUrlExtensions.GetIdentityServerRelativeUrl, ReturnUrlParser.ParseAsync and OidcReturnUrlParser.ParseAsync methods may incorrectly return non-null, and the ReturnUrlParser.IsValidReturnUrl and OidcReturnUrlParser.IsValidReturnUrl methods may incorrectly return true for malicious Urls.

Patches

IdentityServer4 is no longer supported and will not be receiving updates. Please consider updating to Duende.IdentityServer.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
.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 IdentityServer4, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of IdentityServer4 has shipped for GHSA-55p7-v223-x366 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-55p7-v223-x366 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-55p7-v223-x366. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact 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. ### Affected Methods - In the `DefaultIdentityServerInteractionService`, the `GetAuthorizationContextAsync` method may return non-null and the `IsValidReturnUrl` method may return true for malicious Urls, indicating incorrectly that they can be safely redirected to. _UI code calling these two methods is the most commonly used code path t

O3 Security · Impact-Aware SCA

Is GHSA-55p7-v223-x366 in your dependencies?

O3 Security finds GHSA-55p7-v223-x366 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works