---
id: "CVE-2026-124491"
page: "https://infrastack.ai/live/CVE-2026-124491"
kind: "vulnerability"
aliases: ["CVE-2026-124491"]
title: "SunEditor: uploaded file names run scripts in editor users' browsers"
severity: "medium"
cvss: 6.4
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["javascript", "package", "rich-text-editor", "suneditor"]
not_affected_if: ["no-file-upload-plugin", "no-user-uploads"]
published_at: "2026-11-08T14:18:18+00:00"
first_seen_at: "2026-11-08T14:48:41+00:00"
updated_at: "2026-11-08T14:50:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-124491", "first_seen_at": "2026-11-08T14:48:41+00:00"}]
exploit_sources: []
---

# SunEditor: uploaded file names run scripts in editor users' browsers

Link for people: https://infrastack.ai/live/CVE-2026-124491 (this .md is for agents)

SunEditor, a JavaScript rich-text editor, puts server-returned file names into the page without escaping them. An attacker who uploads a file with HTML in its name can run JavaScript in the browser of anyone who loads that content, which can lead to session theft.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed `suneditor` version in `package.json` or the lockfile; versions below `3.4.0` are affected.
- Check whether the FileUpload plugin is enabled in the editor configuration.

## Fix

- `suneditor` upgrade to `3.4.0` or later

## Timeline

- 2026-11-08T14:48:41+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-124491

## Documents

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

## From the sources

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.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_