# CVE-2018-25353: Redaxo CMS Mediapool Addon 5.5.1 Arbitrary File Upload

> Authenticated attackers can upload executable files by bypassing extension blacklists, leading to arbitrary code execution on Redaxo CMS installations.

- **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:** 23 May 2026
- **Updated:** 26 May 2026
- **Also known as:** GHSA-x5jj-8qq8-g67q

## What is CVE-2018-25353?

CVE-2018-25353 is a high-severity vulnerability in Redaxo CMS Mediapool, published on 23 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Redaxo CMS Mediapool Addon 5.5.1 and older contains an arbitrary file upload vulnerability that allows authenticated users to bypass file extension blacklist restrictions. Attackers with editor accounts can upload executable files by using obfuscated extensions like php71 or php53 to evade the blacklist filter and execute arbitrary code.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2018-25353?


## How do I fix CVE-2018-25353?

No fix has been published for CVE-2018-25353 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-25353 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-25353 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-25353 and fix it if it is affected.

What it is: CVE-2018-25353 is a high-severity vulnerability in Redaxo CMS Mediapool, published on 23 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-2018-25353 exists.

Affected product: Redaxo CMS Mediapool. 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-2018-25353/ (Markdown: https://insights.sbomify.com/CVE-2018-25353/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-25353
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-25353
- OSV: https://osv.dev/vulnerability/CVE-2018-25353

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-25353/
Summaries are generated and may contain mistakes; the official description above is the record.