CVE-2026-124493
SunEditor before 3.4.0 Stored XSS via DocumentType Header textContent
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| suneditor JiHong88 |
≥ 0; < 3.4.0 (affected, semver) 3.4.0 (unaffected, semver) Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 9.3 critical |
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 | CNA: VulnCheck |
| 4.0 / 9.3 critical |
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD: [email protected] |
Exploit evidence
- https://github.com/JiHong88/suneditor/security/advisories/GHSA-h9pq-57qf-vvfh
exploit · ADP: CISA-ADP
References
- https://github.com/JiHong88/suneditor/security/advisories/GHSA-h9pq-57qf-vvfhCNA: VulnCheck · vendor-advisory
- https://www.vulncheck.com/advisories/suneditor-before-3.4.0-stored-xss-via-documenttype-header-textcontentCNA: VulnCheck · third-party-advisory
- https://github.com/JiHong88/suneditor/security/advisories/GHSA-h9pq-57qf-vvfhADP: CISA-ADP · exploit
- https://github.com/JiHong88/suneditor/security/advisories/GHSA-h9pq-57qf-vvfh[email protected]
- https://www.vulncheck.com/advisories/suneditor-before-3.4.0-stored-xss-via-documenttype-header-textcontent[email protected]
- https://github.com/JiHong88/suneditor/security/advisories/GHSA-h9pq-57qf-vvfh134c704f-9b21-4f2e-91b3-4a467353bcc0
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