CVE-2023-6841 — keycloak-core
HIGHCVE-2023-6841 is a high-severity (CVSS 7.5) CWE-231 vulnerability in org.keycloak:keycloak-core. A fix is available for org.keycloak:keycloak-core — see the affected versions and patch details below.
Keycloak: amount of attributes per object is not limited and it may lead to dos
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-2023-6841.
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-coreReal-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 denial of service vulnerability was found in keycloak where the amount of attributes per object is not limited, an attacker by sending repeated HTTP requests could cause a resource exhaustion when the application send back rows with long attribute values. The issue is fixed in Keycloak 24 with the introduction of the User Profile feature.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.keycloak:keycloak-core | all versions | 24.0.0org.keycloak:keycloak-core:24.0.0 |
Affected Products
keycloakredhatsingle 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-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.keycloak:keycloak-core to 24.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-6841 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
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 Hat has evaluated this vulnerability and it only affects the Red Hat Single Sign-On (RHSSO).
This CVE is mitigated by the 'User Profile' functionality, which was introduced in Keycloak 24. This feature introduces additional validation which prevents this vulnerability from being exploited.Source: Red Hat security advisory for CVE-2023-6841 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2023-6841 in your dependencies?
Find it across Maven, including transitive dependencies.