CVE-2023-6291 is a high-severity (CVSS 7.1) Open Redirect vulnerability in org.keycloak:keycloak-services. A fix is available for org.keycloak:keycloak-services — see the affected versions and patch details below.
Keycloak: redirect_uri validation bypass
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-2023-6291.
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
An issue was found in the redirect_uri validation logic that allows for a bypass of otherwise explicitly allowed hosts.
The problem arises in the verifyRedirectUri method, which attempts to enforce rules on user-controllable input, but essentially causes a desynchronization in how Keycloak and browsers interpret URLs. Keycloak, for example, receives "www%2ekeycloak%2eorg%2fapp%2f:[email protected]" and thinks the authority to be keycloak.org when it is actually example.com. This happens because the validation logic is performed on a URL decoded version, which no longer represents the original input.
Acknowledgements
Karel Knibbe
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.keycloak:keycloak-services | all versions | 23.0.3org.keycloak:keycloak-services:23.0.3 |
Affected Products
keycloakredhatmigration toolkit for applicationsredhatopenshift container platformredhatopenshift container platform for ibm zredhatopenshift container platform for linuxoneredhatopenshift container platform for powerredhatDetection & 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 23.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-6291 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.
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.
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2023-6291 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat build of Keycloak 22 | rhbk/keycloak-operator-bundle:22.0.7-1 | RHSA-2023:7861 |
| Red Hat build of Keycloak 22.0.7 | see advisory | RHSA-2023:7860 |
| Red Hat Single Sign-On 7 | rh-sso7-keycloak | RHSA-2024:0804 |
| Red Hat Single Sign-On 7.6 for RHEL 7 | rh-sso7-keycloak-0:18.0.11-2.redhat_00003.1.el7sso | RHSA-2023:7854 |
| Red Hat Single Sign-On 7.6 for RHEL 7 | rh-sso7-keycloak-0:18.0.12-1.redhat_00001.1.el7sso | RHSA-2024:0798 |
| Red Hat Single Sign-On 7.6 for RHEL 8 | rh-sso7-keycloak-0:18.0.11-2.redhat_00003.1.el8sso | RHSA-2023:7856 |
| Red Hat Single Sign-On 7.6 for RHEL 8 | rh-sso7-keycloak-0:18.0.12-1.redhat_00001.1.el8sso | RHSA-2024:0799 |
| Red Hat Single Sign-On 7.6 for RHEL 9 | rh-sso7-keycloak-0:18.0.11-2.redhat_00003.1.el9sso | RHSA-2023:7855 |
Frequently Asked Questions
Is CVE-2023-6291 in your dependencies?
Find it across Maven, including transitive dependencies.