CVE-2026-50202: Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Security.Auth...

Description

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Security.Authentication.CloudFoundryBase prior to version 3.4.0, Steeltoe.Security.Authentication.JwtBearer prior to version 4.2.0, and Steeltoe.Security.Authentication.OpenIdConnect prior to version 4.2.0, the JWT signing key cache in `TokenKeyResolver` uses `kid` as the sole cache key without namespacing by authority. In applications with multiple `JwtBearer` schemes pointing to different identity providers, a key fetched for one scheme can satisfy token validation for another. Additionally, cached keys have no expiration, so rotated or revoked keys remain trusted until the application process restarts. Steeltoe.Security.Authentication.CloudFoundryBase version 3.4.0, Steeltoe.Security.Authentication.JwtBearer version 4.2.0, and Steeltoe.Security.Authentication.OpenIdConnect version 4.2.0 patch the issue. If an immediate upgrade is not possible: In multi-scheme deployments, configure only one `JwtBearer` scheme per application when different identity providers are required; and/or restart the application process after an identity provider signing key rotation to clear stale cached keys.

Metrics

CVSS 3.1

5.9/10

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N

EPSS Probability

0.29%

20.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-668

References

Timeline

Published: Jun 17, 2026
Last Modified: Jun 22, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-50202?

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Security.Authentication.CloudFoundryBase prior to version 3.4.0, Steeltoe.Security.Authentication.JwtBearer prior to version 4.2.0, and Steeltoe.Security.Authentication.OpenIdConnect prior to version 4.2.0, the JWT signing key cache in `TokenKeyResolver` uses `kid` as the sole cache key without namespacing by authority. In applications with multiple `JwtBearer` schemes pointing to different identity providers, a key fetched for one scheme can satisfy token validation for another. Additionally, cached keys have no expiration, so rotated or revoked keys remain trusted until the application process restarts. Steeltoe.Security.Authentication.CloudFoundryBase version 3.4.0, Steeltoe.Security.Authentication.JwtBearer version 4.2.0, and Steeltoe.Security.Authentication.OpenIdConnect version 4.2.0 patch the issue. If an immediate upgrade is not possible: In multi-scheme deployments, configure only one `JwtBearer` scheme per application when different identity providers are required; and/or restart the application process after an identity provider signing key rotation to clear stale cached keys.

How severe is CVE-2026-50202?

CVE-2026-50202 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.

How do I fix CVE-2026-50202?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.