CVE-2023-2422 is a high-severity (CVSS 7.1) CWE-295 vulnerability in org.keycloak:keycloak-services. A fix is available for org.keycloak:keycloak-services — see the affected versions and patch details below.
Keycloak vulnerable to Improper Client Certificate Validation for OAuth/OpenID clients
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-2422.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.keycloak:keycloak-servicesReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
A flaw was found in Keycloak. A Keycloak server configured to support mTLS authentication for OAuth/OpenID clients does not properly verify the client certificate chain. A client that possesses a proper certificate can authorize itself as any other client, therefore, access data that belongs to other clients.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.keycloak:keycloak-services | all versions | 21.1.2org.keycloak:keycloak-services:21.1.2 |
Affected Products
keycloakredhatopenshift container platformredhatsingle sign-onredhatDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.keycloak:keycloak-services, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.keycloak:keycloak-services to 21.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-2422 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Single Sign-On 7 | see advisory | RHSA-2023:3892 |
| Red Hat Single Sign-On 7.6 for RHEL 7 | rh-sso7-keycloak-0:18.0.8-1.redhat_00001.1.el7sso | RHSA-2023:3883 |
| Red Hat Single Sign-On 7.6 for RHEL 8 | rh-sso7-keycloak-0:18.0.8-1.redhat_00001.1.el8sso | RHSA-2023:3884 |
| Red Hat Single Sign-On 7.6 for RHEL 9 | rh-sso7-keycloak-0:18.0.8-1.redhat_00001.1.el9sso | RHSA-2023:3885 |
| RHEL-8 based Middleware Containers | rh-sso-7/sso76-openshift-rhel8:7.6-24 | RHSA-2023:3888 |
Frequently Asked Questions
Is CVE-2023-2422 in your dependencies?
Find it across Maven, including transitive dependencies.