CVE-2026-50202 json
Steeltoe's static JWKS cache shared across schemes and never invalidated
published 2026-06-17 4 mo ago modified 2026-07-02 4 mo ago also GHSA-7fqc-p256-7pwj , EUVD-2026-37817
- cvss
- 5.9
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 21%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- nuget Steeltoe.Security.Authentication.JwtBearer 4.2.0
- nuget Steeltoe.Security.Authentication.OpenIdConnect 4.2.0
- nuget Steeltoe.Security.Authentication.CloudFoundryBase 3.4.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 4 mo ago
Exploit prediction
0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N |
| GitHub | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | Steeltoe.Security.Authentication.JwtBearer | <4.2.0 |
4.2.0 |
| nuget | Steeltoe.Security.Authentication.OpenIdConnect | <4.2.0 |
4.2.0 |
| nuget | Steeltoe.Security.Authentication.CloudFoundryBase | <3.4.0 |
3.4.0 |
Affected products
- SteeltoeOSS Steeltoe.Security.Authentication.CloudFoundryBase
- SteeltoeOSS Steeltoe.Security.Authentication.JwtBearer
- SteeltoeOSS Steeltoe.Security.Authentication.OpenIdConnect
Classification
- Weakness
-
- CWE-668 Exposure of Resource to Wrong Sphere
References
-
github.com
/SteeltoeOSS/Steeltoe/commit/04db2ace3b806bfe0260bb7d4bda340f241eff48
web
-
github.com
/SteeltoeOSS/Steeltoe/commit/17b27b8be546ae3f83a2f6e91d45e0c84c5314b7
web
-
github.com
/SteeltoeOSS/security-advisories/security/advisories/GHSA-7fqc-p256-7pwj
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-50202
advisory
-
github.com
/SteeltoeOSS/security-advisories
package
Sources
- CVE List CVE-2026-50202
- GitHub Advisory GHSA-7fqc-p256-7pwj
- NVD CVE-2026-50202
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