Keycloak vulnerable to reflected XSS via wildcard in OIDC redirect_uriGHSA-cvg2-7c3j-g36j
MEDIUMFix: keycloak/keycloak@15a21bfGHSA-cvg2-7c3j-g36j is a medium-severity (CVSS 4.6) Cross-site Scripting (XSS) vulnerability in org.keycloak:keycloak-services. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for org.keycloak:keycloak-services — see the affected versions and patch details below.
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 that prevents certain schemes in redirects, but permits them if a wildcard is appended to the token. This issue could allow an attacker to submit a specially crafted request leading to cross-site scripting (XSS) or further attacks. This flaw is the result of an incomplete fix for CVE-2020-10748.
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
keycloakredhatopenshift container platformredhatopenshift container platform for powerredhatopenshift 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 23.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cvg2-7c3j-g36j is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
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 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 GHSA-cvg2-7c3j-g36j in your dependencies?
Find it across Maven, including transitive dependencies.