CVE-2026-40520 PUBLISHED

FreePBX api module Command Injection via GraphQL

Assigner: VulnCheck
Reserved: 13.04.2026 Published: 21.04.2026 Updated: 21.04.2026

FreePBX api module version 17.0.8 and prior contain a command injection vulnerability in the initiateGqlAPIProcess() function where GraphQL mutation input fields are passed directly to shell_exec() without sanitization or escaping. An authenticated user with a valid bearer token can send a GraphQL moduleOperations mutation with backtick-wrapped commands in the module field to execute arbitrary commands on the underlying host as the web server user.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.6

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	High
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 7.2

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	High	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	FreePBX
Product	api
Versions	Default: unaffected affected from 0 to 17.0.8 (incl.) Version 5f194e39a47e5481e8947f9694304d32724175f6 is unaffected

Credits

M. Cory Billington of theyhack.me reporter

References

Problem Types

CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') CWE