How severe is CVE-2023-6544?

CVE-2023-6544 has a CVSS score of 5.4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-6544?

CVE-2023-6544 affects the following packages: org.keycloak:keycloak-services (Maven), org.keycloak:keycloak-services (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-6544?

Update org.keycloak:keycloak-services to 22.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-6544 is resolved across your whole dependency graph.

How do I detect CVE-2023-6544 in my Maven dependencies?

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.

How do I mitigate CVE-2023-6544 if there is no patch (or I can't update yet)?

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.

Is CVE-2023-6544 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-6544 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-6544?

CVE-2023-6544 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 65th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-6544?

CVE-2023-6544 is classified as CWE-625 (CWE-625). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-6544 published, and has it been updated?

CVE-2023-6544 was published on April 25, 2024 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2023-6544 — keycloak-services

MEDIUM

CVE-2023-6544 is a medium-severity (CVSS 5.4) CWE-625 vulnerability in org.keycloak:keycloak-services. A fix is available for org.keycloak:keycloak-services — see the affected versions and patch details below.

Keycloak: authorization bypass

Also known asGHSA-46c8-635v-68r2

Published

Apr 25, 2024

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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-2023-6544.

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs65th percentile — riskier than 65% of all scored CVEsHighest risk

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

2 pkgs affected

☕org.keycloak:keycloak-services☕org.keycloak:keycloak-services

Real-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

Due to a permissive regular expression hardcoded for filtering allowed hosts to register a dynamic client, a malicious user with enough information about the environment could benefit and jeopardize an environment with this specific Dynamic Client Registration with TrustedDomain configuration previously unauthorized.

Acknowledgements:

Special thanks to Bastian Kanbach for reporting this issue and helping us improve our security.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.keycloak:keycloak-services`	all versions	22.0.10`org.keycloak:keycloak-services:22.0.10`
☕Maven	`org.keycloak:keycloak-services`	≥ 23.0.0&&< 24.0.3	24.0.3`org.keycloak:keycloak-services:24.0.3`

Detection & mitigation playbook

Open-source dependency

Detect
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 22.0.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-6544 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.

Red HatModerate

Due to the high complexity of this attack, Red Hat considers this a Moderate impact.

Workaround published by Red Hat

No mitigation is currently available for this flaw.

Source: Red Hat security advisory for CVE-2023-6544 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat build of Keycloak 22	`rhbk/keycloak-operator-bundle:22.0.10-1`	RHSA-2024:1867
Red Hat build of Keycloak 22.0.10	`keycloak-core`	RHSA-2024:1868
Red Hat Single Sign-On 7.6 for RHEL 7	`rh-sso7-keycloak-0:18.0.13-1.redhat_00001.1.el7sso`	RHSA-2024:1860
Red Hat Single Sign-On 7.6 for RHEL 8	`rh-sso7-keycloak-0:18.0.13-1.redhat_00001.1.el8sso`	RHSA-2024:1861
Red Hat Single Sign-On 7.6 for RHEL 9	`rh-sso7-keycloak-0:18.0.13-1.redhat_00001.1.el9sso`	RHSA-2024:1862
RHEL-8 based Middleware Containers	`rh-sso-7/sso76-openshift-rhel8:7.6-46`	RHSA-2024:1864
RHSSO 7.6.8	`rh-sso7-keycloak`	RHSA-2024:1866

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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