# CVE-2024-56156: Halo Vulnerable to Stored XSS and RCE via File Upload Bypass

> Attackers can bypass file validation to upload malicious files, leading to stored XSS and potential remote code execution in Halo.

- **Severity:** Medium 5.5 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:L/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Apr 2025
- **Updated:** 3 Feb 2026
- **Also known as:** GHSA-99mc-ch53-pqh9

## What is CVE-2024-56156?

CVE-2024-56156 is a medium-severity vulnerability in halo-dev halo, published on 25 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Halo is an open source website building tool. Prior to version 2.20.13, a vulnerability in Halo allows attackers to bypass file type validation controls. This bypass enables the upload of malicious files including executables and HTML files, which can lead to stored cross-site scripting attacks and potential remote code execution under certain circumstances. This issue has been patched in version 2.20.13.

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

## Which versions are affected by CVE-2024-56156?

It affects 1 product.


Products: Halo Halo.

## How do I fix CVE-2024-56156?

No fix has been published for CVE-2024-56156 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-56156 being exploited?

There is no known exploitation of CVE-2024-56156 in the wild and no public exploit code.

## Other vulnerabilities in halo-dev halo

- [CVE-2022-32994](https://insights.sbomify.com/CVE-2022-32994/): File upload in n/a (critical 9.8)
- [CVE-2022-32995](https://insights.sbomify.com/CVE-2022-32995/): Server-side request forgery in n/a (critical 9.8)
- [CVE-2020-18980](https://insights.sbomify.com/CVE-2020-18980/): Code injection in n/a (critical 9.8)
- [CVE-2020-21522](https://insights.sbomify.com/CVE-2020-21522/): Path traversal in n/a (critical 9.8)
- [CVE-2020-21523](https://insights.sbomify.com/CVE-2020-21523/): Code injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-56156 and fix it if it is affected.

What it is: CVE-2024-56156 is a medium-severity vulnerability in halo-dev halo, published on 25 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-56156 in the wild and no public exploit code.

Affected product: halo-dev halo. 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-2024-56156/ (Markdown: https://insights.sbomify.com/CVE-2024-56156/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56156
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56156
- OSV: https://osv.dev/vulnerability/CVE-2024-56156

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56156/
Summaries are generated and may contain mistakes; the official description above is the record.