CVE-2026-124493

SunEditor before 3.4.0 Stored XSS via DocumentType Header textContent

Published Nov 8, 2026 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Jihong88
Jihong88 suneditor
Vendors & Products Jihong88
Jihong88 suneditor
Type Values Removed Values Added
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.
Title SunEditor before 3.4.0 Stored XSS via DocumentType Header textContent
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 12, 2026, 2:12 PM
Reserved
Nov 8, 2026, 2:21 AM
Status
Awaiting Analysis
Published
Nov 8, 2026, 2:18 PM
Modified
Nov 12, 2026, 8:28 PM