# CVE-2026-22799: emlog Arbitrary File Upload Vulnerability

> Authenticated attackers can upload malicious PHP scripts via the REST API to achieve remote code execution on emlog servers.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Jan 2026
- **Updated:** 13 Jan 2026
- **Also known as:** CLEANSTART-2026-FP53040, GHSA-p837-mrw9-5x5j

## What is CVE-2026-22799?

CVE-2026-22799 is a critical vulnerability in Emlog Emlog, published on 12 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Emlog is an open source website building system. emlog v2.6.1 and earlier exposes a REST API endpoint (/index.php?rest-api=upload) for media file uploads. The endpoint fails to implement proper validation of file types, extensions, and content, allowing authenticated attackers (with a valid API key or admin session cookie) to upload arbitrary files (including malicious PHP scripts) to the server. An attacker can obtain the API key either by gaining administrator access to enable the REST API setting, or via information disclosure vulnerabilities in the application. Once uploaded, the malicious PHP file can be executed to gain remote code execution (RCE) on the target server, leading to full server compromise.

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

## Which versions are affected by CVE-2026-22799?

It affects 1 product.


Products: Emlog Emlog.

## How do I fix CVE-2026-22799?

Upgrade to a fixed version.

## Is CVE-2026-22799 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22799 exists.

## Other vulnerabilities in Emlog Emlog

- [CVE-2025-29401](https://insights.sbomify.com/CVE-2025-29401/): File upload in n/a (critical 9.8)
- [CVE-2025-25783](https://insights.sbomify.com/CVE-2025-25783/): File upload in n/a (critical 9.8)
- [CVE-2023-44973](https://insights.sbomify.com/CVE-2023-44973/): File upload in n/a (critical 9.8)
- [CVE-2023-44974](https://insights.sbomify.com/CVE-2023-44974/): File upload in n/a (critical 9.8)
- [CVE-2023-43291](https://insights.sbomify.com/CVE-2023-43291/): Deserialization in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-22799 and fix it if it is affected.

What it is: CVE-2026-22799 is a critical vulnerability in Emlog Emlog, published on 12 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22799 exists.

Affected product: Emlog Emlog. 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-2026-22799/ (Markdown: https://insights.sbomify.com/CVE-2026-22799/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22799
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22799
- OSV: https://osv.dev/vulnerability/CVE-2026-22799

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-22799/
Summaries are generated and may contain mistakes; the official description above is the record.