CVE-2026-124491— SunEditor before 3.4.0 Stored XSS via FileUpload Plugin Filename

Quick assessment

Affected

JiHong88 suneditor

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

SunEditor 3.4.0 之前的版本在 FileUpload 插件的方法中存在存储型跨站脚本（XSS）漏洞。该漏洞源于该方法将服务器返回的文件名直接赋值给，而未进行转义处理。攻击者可上传带有 HTML 内容的文件名，从而绕过的过滤机制。当受害者加载相关内容或画廊项时，恶意 JavaScript 将在其浏览器中执行，可能导致会话劫持。

CVSS 6.4 · Medium Updated Nov 08, 2026

Possible ATT&CK Techniques 2 AI

T1055 · Process Injection T1190 · Exploit Public-Facing Application

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Vulnerability Information

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Vulnerability Title

SunEditor before 3.4.0 Stored XSS via FileUpload Plugin Filename

Source: CVE Program / CVE List V5

Vulnerability Description

SunEditor before 3.4.0 contains a stored cross-site scripting vulnerability in the FileUpload plugin create() method that assigns server-returned file names to innerHTML without escaping. Attackers can upload files with HTML-laden names that bypass html.clean() and execute JavaScript in victims' browsers when content or gallery items load, enabling session theft.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Source: CVE Program / CVE List V5

Vulnerability Type

在Web页面生成时对输入的转义处理不恰当(跨站脚本)

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
JiHong88	suneditor	0 ~ 3.4.0	-

II. Public POCs for CVE-2026-124491

#	POC Description	Source Link	Shenlong Link

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No public POC found.

III. Intelligence Information for CVE-2026-124491

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Other References for CVE-2026-124491 (2)

https://github.com/JiHong88/suneditor/security/advisories/GHSA-2w4v-r3v4-f5h4 vendor-advisory
https://www.vulncheck.com/advisories/suneditor-before-3.4.0-stored-xss-via-fileupload-plugin-filename third-party-advisory

https://www.cve.org/CVERecord?id=CVE-2026-124491

Same Patch Batch · JiHong88 · 2026-11-08 · 5 CVEs total

CVE-2026-124493	9.3 CRITICAL	SunEditor before 3.4.0 Stored XSS via DocumentType Header textContent
CVE-2026-124494	9.3 CRITICAL	SunEditor before 3.4.0 Stored XSS via &colon; Entity Sanitizer Bypass
CVE-2026-124492	7.6 HIGH	SunEditor before 3.4.0 Stored XSS via Link Modal Bookmark List
CVE-2026-124422	6.1 MEDIUM	SunEditor 3.0.0 before 3.4.0 Stored XSS via html.clean() Iframe Placeholder

IV. Related Vulnerabilities

Same product: suneditor

Same vendor: JiHong88

Same weakness: CWE-79