CVE-2023-0264 is a high-severity (CVSS 8.7) Improper Authentication vulnerability in org.keycloak:keycloak-services. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for org.keycloak:keycloak-services — see the affected versions and patch details below.
Keycloak vulnerable to user impersonation via stolen UUID code
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 Keycloaks OpenID Connect user authentication, which may incorrectly authenticate requests. An authenticated attacker who could obtain information from a user request within the same realm could use that data to impersonate the victim and generate new session tokens. This issue could impact confidentiality, integrity, and availability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.keycloak:keycloak-services | all versions | 21.0.1org.keycloak:keycloak-services:21.0.1 |
Affected Products
keycloakredhatopenshift container platformredhatopenshift container platform for ibm linuxoneredhatopenshift container platform ibm z systemsredhatsingle sign-onredhatResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & 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 21.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-0264 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
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 | rh-sso7-keycloak | RHSA-2023:1049 |
| Red Hat Single Sign-On 7.6 for RHEL 7 | rh-sso7-keycloak-0:18.0.6-1.redhat_00001.1.el7sso | RHSA-2023:1043 |
| Red Hat Single Sign-On 7.6 for RHEL 8 | rh-sso7-keycloak-0:18.0.6-1.redhat_00001.1.el8sso | RHSA-2023:1044 |
| Red Hat Single Sign-On 7.6 for RHEL 9 | rh-sso7-keycloak-0:18.0.6-1.redhat_00001.1.el9sso | RHSA-2023:1045 |
| RHEL-8 based Middleware Containers | rh-sso-7/sso76-openshift-rhel8:7.6-20 | RHSA-2023:1047 |
Frequently Asked Questions
Is CVE-2023-0264 in your dependencies?
Find it across Maven, including transitive dependencies.