CVE-2026-124422 PUBLISHED

SunEditor 3.0.0 before 3.4.0 Stored XSS via html.clean() Iframe Placeholder

Assigner: VulnCheck
Reserved: 08.11.2026 Published: 08.11.2026 Updated: 08.11.2026

SunEditor from 3.0.0 before 3.4.0 contains a stored cross-site scripting vulnerability in html.clean() that rebuilds iframes from data-se-iframe-holder-attrs JSON without filtering srcdoc or uppercase SRC keys. Attackers can inject crafted HTML through paste, html.set, or html.insert to execute script in the host page origin when victims load or paste the content.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CVSS Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	Low	Confidentiality	Low
Attack Complexity	Low	Integrity	Low	Integrity	Low
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS Score: 6.1

Attack Vector	Network	Scope	Changed
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	jihong88
Product	suneditor
Versions	Default: unaffected affected from 3.0.0 to 3.4.0 (excl.)

Credits

kemrec finder
manus-pi finder
EclipsSec finder
Zachariah Mithani (AploSec) finder

References

Problem Types

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE