CVE-2026-40520

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.

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CVSS v3.1 Score

7.2

HIGH

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

EPSS — Exploit Prediction

0.0035

Probability of exploitation

0.58%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-78 OS Command Injection

Affected Products

Vendor	Product	Versions
freepbx	api	< 17.0.8

References

Advisories & Patches

https://github.com/FreePBX/api/commit/5f194e39a47e5481e8947f9694304d32724175f6

Other References

https://github.com/FreePBX/api/blob/5f194e39a47e5481e8947f9694304d32724175f6/Api.class.php#L546C1-L554C3 https://github.com/FreePBX/api/blob/5f194e39a47e5481e8947f9694304d32724175f6/ApiGqlHelper.class.php#L34C1-L36C136 https://www.vulncheck.com/advisories/freepbx-api-module-command-injection-via-graphql

Frequently Asked Questions

What is CVE-2026-40520? +

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. It has a CVSS v3.1 base score of 7.2 (HIGH).

How severe is CVE-2026-40520? +

CVE-2026-40520 has a CVSS v3.1 score of 7.2 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0035, placing it in the 1th percentile for exploitation probability.

What products are affected by CVE-2026-40520? +

CVE-2026-40520 affects products from freepbx, specifically: api. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-40520? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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