What is CVE-2023-4771?

CVE-2023-4771 is a medium-severity vulnerability in Cksource Ckeditor, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-11-16.

How severe is CVE-2023-4771?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2023-4771 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Cksource Ckeditor

CVE-2023-4771

A Cross-Site scripting vulnerability has been found in CKSource CKEditor affecting versions 4.15.1 and earlier. An attacker could send malicious javascript code through the /ckeditor/samples/old/ajax.html file and retrieve an authorized user's information.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2023-11-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.009 (57.4th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 57.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Cksource Ckeditor — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

www.incibe.es/en/incibe-cert/notices/aviso/cross-site-scripting-vulnerability-c… (Third Party Advisory)

Frequently asked questions

What is CVE-2023-4771?: CVE-2023-4771 is a medium-severity vulnerability in Cksource Ckeditor, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-11-16.
How severe is CVE-2023-4771?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2023-4771 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.