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Fencer Vulns
low 3.8

CVE-2023-0091 json

Keycloak has lack of validation of access token on client registrations endpoint

published 2023-01-11 3 y ago modified 2026-06-17 4 mo ago also GHSA-v436-q368-hvgg , EUVD-2023-0552

cvss
3.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

A flaw was found in Keycloak, where it did not properly check client tokens for possible revocation in its client credential flow. This flaw allows an attacker to access or modify potentially sensitive information.

Patch / fix

  • maven org.keycloak:keycloak-core 20.0.3
  • rh-sso7-keycloak red hat single sign on 7.6 18.0.6-1.redhat_00001.1.el7sso
  • rh-sso7-keycloak-server red hat single sign on 7.6 18.0.6-1.redhat_00001.1.el7sso
  • rh-sso7-keycloak red hat single sign on 7.6 18.0.6-1.redhat_00001.1.el8sso
  • rh-sso7-keycloak-server red hat single sign on 7.6 18.0.6-1.redhat_00001.1.el8sso
  • rh-sso7-keycloak red hat single sign on 7.6 18.0.6-1.redhat_00001.1.el9sso
  • rh-sso7-keycloak-server red hat single sign on 7.6 18.0.6-1.redhat_00001.1.el9sso

red hat advisories RHSA-2023:1043RHSA-2023:1044RHSA-2023:1045

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-0091 updated cvss 3.8

keycloak: Client Registration endpoint does not check token revocation

  • Red Hat Middleware Containers for OpenShift rh-sso-7/sso76-openshift-rhel8 7.6-20
    fixed: vendor fix RHSA-2023:1047
  • Red Hat Single Sign-On 7
    fixed: vendor fix RHSA-2023:1049
  • Red Hat Single Sign-On 7.6 for RHEL 7 Server rh-sso7-keycloak 18.0.6-1.redhat_00001.1.el7sso, rh-sso7-keycloak-server 18.0.6-1.redhat_00001.1.el7sso
    fixed: vendor fix RHSA-2023:1043
  • Red Hat Single Sign-On 7.6 for RHEL 8 rh-sso7-keycloak 18.0.6-1.redhat_00001.1.el8sso, rh-sso7-keycloak-server 18.0.6-1.redhat_00001.1.el8sso
    fixed: vendor fix RHSA-2023:1044
  • Red Hat Single Sign-On 7.6 for RHEL 9 rh-sso7-keycloak 18.0.6-1.redhat_00001.1.el9sso, rh-sso7-keycloak-server 18.0.6-1.redhat_00001.1.el9sso
    fixed: vendor fix RHSA-2023:1045

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
19 mo ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 3.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
NVD 3.1 3.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
CNA 3.1 3.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
maven org.keycloak:keycloak-core
<20.0.3
20.0.3

Affected products

  • redhat.com Keycloak

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.