CVE-2026-124493

Published Nov 8, 2026 CWE-79

Description

SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability in the DocumentType constructor that injects header textContent into innerHTML without HTML escaping. Attackers can store entity-encoded HTML in h1-h6 headers that executes JavaScript when editors using document:header mode initialize, enabling session cookie theft.

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EPSS — Exploit Prediction

0.0034
Probability of exploitation
0.28%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Frequently Asked Questions

What is CVE-2026-124493? +
SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability in the DocumentType constructor that injects header textContent into innerHTML without HTML escaping. Attackers can store entity-encoded HTML in h1-h6 headers that executes JavaScript when editors using document:header mode initialize, enabling session cookie theft.
How do I check if I'm vulnerable to CVE-2026-124493? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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