CVE-2026-8922Public exploitNetwork attack vector

Revoked-token reuse via omitted realm cutoff check

Published May 19, 2026 · Updated May 19, 2026

Improper authentication in Red Hat build of Keycloak 26.4 and 26.6 allows remote authenticated users to reuse revoked OIDC tokens. AccessTokenIntrospectionProvider checks the client's notBefore cutoff but omits the realm cutoff, so introspection returns active=true for tokens invalidated realm-wide. Exploitation requires both cutoffs, a token issued between them, and a resource server that trusts introspection, preserving access within that token's permissions.

CVSS severity5.4
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Red Hat build of Keycloak 26.4 and 26.6 allows remote authenticated users to reuse revoked OIDC tokens. AccessTokenIntrospectionProvider checks the client's notBefore cutoff but omits the realm cutoff, so introspection returns active=true for tokens invalidated realm-wide. Exploitation requires both cutoffs, a token issued between them, and a resource server that trusts introspection, preserving access within that token's permissions.

The record

CVE
CVE-2026-8922
Published
May 19, 2026
Updated
May 19, 2026
Vendor
389 Directory Server
Product
Red Hat build of Keycloak
Classifications
CWE-303, T1550.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 19, 2026CVE publishedPublication date reported by the CVE source.
  2. May 19, 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?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

389 Directory Server · Red Hat build of KeycloakAffected versions are unavailable in this record.

Published CVSS scores

5.4Red Hat, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-303Incorrect Implementation of Authentication Algorithm
T1550.001Use Alternate Authentication Material: Application Access Token

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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