CVE-2026-40520
FreePBX api module Command Injection via GraphQL
Description
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.
INFO
Published Date :
April 21, 2026, 1:16 p.m.
Last Modified :
April 23, 2026, 4:27 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update FreePBX to version 17.0.9 or later.
- Sanitize and escape all shell command inputs.
- Restrict bearer token privileges.
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-2026-40520.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40520 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-2026-40520
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-2026-40520 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40520 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.
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Initial Analysis by [email protected]
Apr. 23, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:freepbx:api:*:*:*:*:*:*:*:* versions up to (excluding) 17.0.8 Added Reference Type VulnCheck: https://github.com/FreePBX/api/blob/5f194e39a47e5481e8947f9694304d32724175f6/Api.class.php#L546C1-L554C3 Types: Product Added Reference Type VulnCheck: https://github.com/FreePBX/api/blob/5f194e39a47e5481e8947f9694304d32724175f6/ApiGqlHelper.class.php#L34C1-L36C136 Types: Product Added Reference Type VulnCheck: https://github.com/FreePBX/api/commit/5f194e39a47e5481e8947f9694304d32724175f6 Types: Patch Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/freepbx-api-module-command-injection-via-graphql Types: Third Party Advisory -
New CVE Received by [email protected]
Apr. 21, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:H/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 CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-78 Added Reference https://github.com/FreePBX/api/blob/5f194e39a47e5481e8947f9694304d32724175f6/Api.class.php#L546C1-L554C3 Added Reference https://github.com/FreePBX/api/blob/5f194e39a47e5481e8947f9694304d32724175f6/ApiGqlHelper.class.php#L34C1-L36C136 Added Reference https://github.com/FreePBX/api/commit/5f194e39a47e5481e8947f9694304d32724175f6 Added Reference https://www.vulncheck.com/advisories/freepbx-api-module-command-injection-via-graphql