9.3
CRITICAL CVSS 4.0
CVE-2026-73665
FreePBX UCP: Unauthenticated remote code execution via socket.io namespace auth bypass and AMI action injection
Description

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.

INFO

Published Date :

Aug. 13, 2026, 10:17 p.m.

Last Modified :

Aug. 13, 2026, 10:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-73665 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 CRITICAL [email protected]
Solution
Update FreePBX to version 17.0.9 or later to address authentication bypass and arbitrary command execution vulnerabilities.
  • Update FreePBX to version 17.0.9.
  • Apply security patches for FreePBX.
  • Verify authentication controls for custom namespaces.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-73665.

URL Resource
https://github.com/FreePBX/security-reporting/security/advisories/GHSA-37j8-fhxx-9vhp
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-73665 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-73665 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-73665 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-73665 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 13, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'FreePBX', 'product': 'ucp', 'versions': [{'status': 'affected', 'version': '< 17.0.9'}]}]
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-862
    Added Reference https://github.com/FreePBX/security-reporting/security/advisories/GHSA-37j8-fhxx-9vhp
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.