Is CVE-2026-26978 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-26978 being exploited in the wild.

How severe is CVE-2026-26978?

Informational severity, with a CVSS score of 8.6, published 18 May 2026.

Which products and versions are affected?

FreePBX Backup Module < 16.0.71, < 17.0.6.

Is there a fix for CVE-2026-26978?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-26978 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-26978?

Check whether you run FreePBX Backup Module at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-26978: FreePBX Backup Module insecure deserialization in restore operation

Q: Is there a fix for CVE-2026-26978?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

Q: How is CVE-2026-26978 attacked?

It is attacked over the network, in a network appliance.

Q: Am I affected by CVE-2026-26978?

Check whether you run FreePBX Backup Module at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-26978 · Severity: info · CVSS 8.6 · Published 2026-05-18

FreePBX is an open-source communication platform used for managing IP-based phone systems. A security vulnerability in its backup and restore module allows an authorized user to execute malicious code on the server by uploading a specially crafted backup file. This could lead to a full system compromise, allowing an attacker to intercept communications or disrupt phone services.

Vendors: FreePBX.

Quick answers

Is CVE-2026-26978 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-26978 being exploited in the wild.
How severe is CVE-2026-26978?: Informational severity, with a CVSS score of 8.6, published 18 May 2026.
Which products and versions are affected?: FreePBX Backup Module < 16.0.71, < 17.0.6.
Is there a fix for CVE-2026-26978?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-26978 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-26978?: Check whether you run FreePBX Backup Module at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A deserialization vulnerability (CWE-502) exists in the FreePBX backup module's restore functionality. During the restoration process, the application extracts files from a user-provided tar archive and passes the contents of manifest files directly to the PHP unserialize() function without prior validation or class restrictions. An attacker with sufficient privileges to perform a restore or write access to backup files can craft a malicious archive containing a PHP gadget chain to achieve Remote Code Execution (RCE). The exploit runs with the privileges of the web server user (typically 'asterisk' or 'www-data'). The issue is resolved in versions 16.0.71 and 17.0.6 by implementing json_decode() and restricting unserialize() options.

Affected products

FreePBX FreePBX Backup Module < 16.0.71, < 17.0.6

Timeline

2026-05-11: advisory: GitHub Security Advisory published
2026-05-18: disclosed: CVE published to NVD

References

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