Exposure of Resource to Wrong Sphere Affecting steeltoe.security.authentication.openidconnect package, versions [,4.2.0)
Threat Intelligence
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The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DOTNET-STEELTOESECURITYAUTHENTICATIONOPENIDCONNECT-17373298
- published18 Jun 2026
- disclosed18 Jun 2026
- creditUnknown
Introduced: 18 Jun 2026
NewCVE-2026-50202 (opens in a new tab)How to fix?
Upgrade Steeltoe.Security.Authentication.OpenIdConnect to version 4.2.0 or higher.
Overview
Affected versions of this package are vulnerable to Exposure of Resource to Wrong Sphere in the TokenKeyResolver function. An attacker can bypass authentication and gain unauthorized access by exploiting the shared static JWKS cache across multiple schemes, allowing a key fetched for one identity provider to validate tokens for another. This also enables the use of stale or revoked keys due to the lack of cache expiration.
Note:
This is only exploitable if multiple JwtBearer schemes are configured with different identity providers in the same application.
Workaround
This vulnerability can be mitigated by configuring only one JwtBearer scheme per application when different identity providers are required, and/or restarting the application process after an identity provider signing key rotation to clear stale cached keys.