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


- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 8 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-2w4v-r3v4-f5h4, GHSA-m98v-phcq-735w

## What is CVE-2026-124491?

CVE-2026-124491 is a medium-severity vulnerability in JiHong88 suneditor, published on 8 Nov 2026. 

### Official 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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-124491?


## How do I fix CVE-2026-124491?

No fix has been published for CVE-2026-124491 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-124491 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124491 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-124491 and fix it if it is affected.

What it is: CVE-2026-124491 is a medium-severity vulnerability in JiHong88 suneditor, published on 8 Nov 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-124491 exists.

Affected product: JiHong88 suneditor. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-124491/ (Markdown: https://insights.sbomify.com/CVE-2026-124491/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-124491
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124491
- OSV: https://osv.dev/vulnerability/CVE-2026-124491

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-124491/
Summaries are generated and may contain mistakes; the official description above is the record.