Summary
Reflected XSS on clients-registrations endpoint
A POST based reflected Cross Site Scripting vulnerability on has been identified in Keycloak. When a malicious request is sent to the client registration endpoint, the error message is not properly escaped, allowing an attacker to execute malicious scripts into the user's browser.
Acknowledgement
Keycloak would like to thank Quentin TEXIER (Pentester at Opencyber) for reporting this issue.
Impact
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is GHSA-M98G-63QJ-FP8J? GHSA-M98G-63QJ-FP8J is a medium-severity cross-site scripting (XSS) vulnerability in org.keycloak:keycloak-parent (maven), affecting versions >= 10.0.0, < 18.0.0. It is fixed in 18.0.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of org.keycloak:keycloak-parent are affected by GHSA-M98G-63QJ-FP8J? org.keycloak:keycloak-parent (maven) versions >= 10.0.0, < 18.0.0 is affected.
- Is there a fix for GHSA-M98G-63QJ-FP8J? Yes. GHSA-M98G-63QJ-FP8J is fixed in 18.0.0. Upgrade to this version or later.
- Is GHSA-M98G-63QJ-FP8J exploitable, and should I be worried? Whether GHSA-M98G-63QJ-FP8J is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-M98G-63QJ-FP8J is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-M98G-63QJ-FP8J? Upgrade
org.keycloak:keycloak-parentto 18.0.0 or later.