---
id: CVE-2026-73665
title: FreePBX is an open source IP PBX
summary: >-
  FreePBX is an open source IP PBX. Prior to 17.0.9, the UCP Node server on
  ports 8001 and 8003 uses io.use(checkAuth) in node/lib/server.js, but
  Socket.IO version 4 applies that middleware only to the default namespace. An
  unauthenticated…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-862
vendor: sangoma
product: freepbx
affected:
  - freepbx < 17.0.9
patched:
  - freepbx 17.0.9
published: '2026-08-13'
updated: '2026-10-09'
sourceUpdated: '2026-10-09T19:29:45.570'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73665'
references:
  - url: >-
      https://github.com/FreePBX/security-reporting/security/advisories/GHSA-37j8-fhxx-9vhp
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00331
epssPercentile: 0.26087
ingestedAt: '2026-09-10T21:05:53.596Z'
---

## Overview

FreePBX is an open source IP PBX. Prior to 17.0.9, the UCP Node server on ports 8001 and 8003 uses io.use(checkAuth) in node/lib/server.js, but Socket.IO version 4 applies that middleware only to the default namespace. An unauthenticated client can connect to custom namespaces that do not consistently invoke checkAuth in node/lib/auth.js and send crafted event values containing carriage-return or newline characters through the Asterisk Manager Interface action path patched by node/lib/asterisk-manager-patch.js, allowing arbitrary commands to execute as the asterisk service user. This issue is fixed in version 17.0.9.

## Affected

- `freepbx < 17.0.9`

## Remediation

Upgrade past the affected range:

- `freepbx 17.0.9`