by Kastro
Paper/Archive/CVE-2026-124493

CVE-2026-124493

JiHong88 suneditor — SunEditor before 3.4.0 Stored XSS via DocumentType Header textContent

CVSS 9.3
critical.is priorityof 100
28
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0No EPSS score.000 × 200.0No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
suneditor< 3.4.03.4.0CNA

Scores by source

VulnCheck (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

References

advisorygithub.com/JiHong88/suneditor/security/advisories/GHSA-h9pq-57qf-vvfhwriteupvulncheck.com/advisories/suneditor-before-3.4.0-stored-xss-via-documenttype-header-textcontent