# CVE-2021-47937: e107 CMS 2.3.0 Authenticated Remote Code Execution via Theme Upload

> Authenticated attackers with theme permissions can upload malicious files to execute arbitrary code on e107 CMS.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 May 2026
- **Updated:** 12 May 2026
- **Also known as:** GHSA-2ggw-79xf-f33h

## What is CVE-2021-47937?

CVE-2021-47937 is a high-severity vulnerability in e107 CMS, published on 10 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

e107 CMS 2.3.0 contains a remote code execution vulnerability that allows authenticated users with theme installation permissions to execute arbitrary commands by uploading malicious theme files. Attackers can upload a crafted theme package through the theme.php endpoint that deploys a web shell to the e107_themes directory, then execute system commands via the payload.php script.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2021-47937?


## How do I fix CVE-2021-47937?

No fix has been published for CVE-2021-47937 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47937 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47937 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47937 and fix it if it is affected.

What it is: CVE-2021-47937 is a high-severity vulnerability in e107 CMS, published on 10 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47937 exists.

Affected product: e107 CMS. 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-2021-47937/ (Markdown: https://insights.sbomify.com/CVE-2021-47937/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47937
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47937
- OSV: https://osv.dev/vulnerability/CVE-2021-47937

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47937/
Summaries are generated and may contain mistakes; the official description above is the record.