medium

CVE-2026-50202

NuGet · Steeltoe.Security.Authentication.JwtBearer

Summary

Steeltoe's static JWKS cache shared across schemes and never invalidated

Severity
medium
CVSS
5.9
EPSS
0.3% (p21)
CWE
CWE-668
Also known as
GHSA-7fqc-p256-7pwj#Steeltoe.Security.Authentication.JwtBearer
Published
2026-07-02
Updated
2026-07-02

Advisory details

Summary

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.

Impact

In multi-scheme deployments, an attacker who controls one identity provider's signing key can forge tokens accepted by other schemes within the same application. For all applications using TokenKeyResolver, a signing key removed from the identity provider's JWKS endpoint remains trusted indefinitely.

Mitigations

If an immediate upgrade is not possible:

References

Related advisories

Is your project exposed to this? Stateward checks every dependency on every pull request and flags it only if your code actually reaches it.

Check my repo

Summarize with AI

ChatGPTClaudePerplexity

Sources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.