CVE-2026-50202Network attack vectorHinoki check available

Token forgery via authority-agnostic non-expiring key cache

Published Jun 17, 2026 · Updated Jun 17, 2026

Improper JWT key caching in affected Steeltoe authentication libraries allows attackers to forge tokens accepted by unintended schemes. TokenKeyResolver indexes signing keys only by kid, not authority, and retains removed keys indefinitely instead of expiring cache entries. Exploitation requires control of one configured identity provider or a previously valid signing key; successful tokens can cross trust boundaries.

CVSS severity5.9
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper JWT key caching in affected Steeltoe authentication libraries allows attackers to forge tokens accepted by unintended schemes. TokenKeyResolver indexes signing keys only by kid, not authority, and retains removed keys indefinitely instead of expiring cache entries. Exploitation requires control of one configured identity provider or a previously valid signing key; successful tokens can cross trust boundaries.

The record

CVE
CVE-2026-50202
Published
Jun 17, 2026
Updated
Jun 17, 2026
Vendor
Steeltoe
Product
Steeltoe.Security.Authentication.JwtBearer
Classifications
CWE-668, T1606
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Steeltoe · Steeltoe.Security.Authentication.JwtBearerversion=< 4.2.0
Steeltoe · Steeltoe.Security.Authentication.OpenIdConnectversion=< 4.2.0
Steeltoe · Steeltoe.Security.Authentication.CloudFoundryBaseversion=< 3.4.0

Published CVSS scores

5.9GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-668Exposure of Resource to Wrong Sphere
T1606Forge Web Credentials

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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