Summary
Affected packages
The vulnerability has been discovered in the AJAX sample available at the samples/old/ajax.html file location. All integrators that use that sample in the production code can be affected.
For more information
Email us at [email protected] if you have any questions or comments about this advisory.
Acknowledgements
The CKEditor 4 team would like to thank Rafael Pedrero and INCIBE (original report) for recognizing and reporting this vulnerability.
Impact
A potential vulnerability has been discovered in one of CKEditor's 4 samples that are shipped with production code. The vulnerability allowed to execute JavaScript code by abusing the AJAX sample. It affects all users using the CKEditor 4 at version < 4.24.0-lts where samples/old/ajax.html is used in a production environment.
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.
CVE-2023-4771 has a CVSS score of 6.1 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.24.0-lts); upgrading removes the vulnerable code path.
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.
Remediation advice
The problem has been recognized and patched. The fix will be available in version 4.24.0-lts.
Frequently Asked Questions
- What is CVE-2023-4771? CVE-2023-4771 is a medium-severity cross-site scripting (XSS) vulnerability in ckeditor4 (npm), affecting versions < 4.24.0-lts. It is fixed in 4.24.0-lts. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2023-4771? CVE-2023-4771 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of ckeditor4 are affected by CVE-2023-4771? ckeditor4 (npm) versions < 4.24.0-lts is affected.
- Is there a fix for CVE-2023-4771? Yes. CVE-2023-4771 is fixed in 4.24.0-lts. Upgrade to this version or later.
- Is CVE-2023-4771 exploitable, and should I be worried? Whether CVE-2023-4771 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 CVE-2023-4771 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 CVE-2023-4771? Upgrade
ckeditor4to 4.24.0-lts or later.