@dapperduckling/keycloak-connector-server has Reflected XSS Vulnerability in Authentication Flow URL HandlingGHSA-w5rq-g9r6-vrcg
HIGHGHSA-w5rq-g9r6-vrcg is a high-severity (CVSS 8.1) Cross-site Scripting (XSS) vulnerability in @dapperduckling/keycloak-connector-server. A fix is available for @dapperduckling/keycloak-connector-server — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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 GHSA-w5rq-g9r6-vrcg.
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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@dapperduckling/keycloak-connector-servernpmDescription
Impact A Reflected Cross-Site Scripting (XSS) vulnerability was discovered in the authentication flow of the application. This issue arises due to improper sanitization of the URL parameters, allowing the URL bar's contents to be injected and reflected into the HTML page. An attacker could craft a malicious URL to execute arbitrary JavaScript in the browser of a victim who visits the link.
Who is impacted? Any application utilizing this authentication library is vulnerable. Users of the application are at risk if they can be lured into clicking on a crafted malicious link.
Patches The vulnerability has been patched in 2.5.5 by ensuring proper sanitization and escaping of user input in the affected URL parameters.
Users are strongly encouraged to upgrade to the following versions:
Workarounds If upgrading is not immediately possible, users can implement the following workarounds:
- Employ a Web Application Firewall (WAF) to block malicious requests containing suspicious URL parameters.
- Apply input validation and escaping directly within the application’s middleware or reverse proxy layer, specifically targeting the affected parameters.
References
- OWASP Cross-Site Scripting (XSS) Cheat Sheet: https://owasp.org/www-community/attacks/xss/
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @dapperduckling/keycloak-connector-server | all versions | 2.5.5npm install @dapperduckling/keycloak-connector-server@2.5.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @dapperduckling/keycloak-connector-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @dapperduckling/keycloak-connector-server to 2.5.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w5rq-g9r6-vrcg 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.
Frequently Asked Questions
Is GHSA-w5rq-g9r6-vrcg in your dependencies?
Find it across npm, including transitive dependencies.