Issabel Framework JWT Signing Key pbxapi/index.php System os command injection

Summaryinfo

A vulnerability described as critical has been identified in Issabel Framework. Affected by this vulnerability is an unknown functionality of the file pbxapi/index.php of the component JWT Signing Key. Such manipulation of the argument System leads to os command injection. This vulnerability is referenced as CVE-2026-89026. It is possible to launch the attack remotely. No exploit is available. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in Issabel Framework (unknown version). It has been rated as critical. Affected by this issue is an unknown code block of the file pbxapi/index.php of the component JWT Signing Key. The manipulation of the argument System with an unknown input leads to a os command injection vulnerability. Using CWE to declare the problem leads to CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. CVE summarizes:

The Issabel Framework, the web framework supporting Issabel PBX software, before commit b97dbaf contains a hard-coded HS256 JWT signing key in the pbxapi index.php file that is identical across every installation, allowing unauthenticated remote attackers to forge valid bearer tokens. Attackers can use the forged token to call the manager originate endpoint with the System application parameter, causing Asterisk to execute arbitrary OS commands as the Asterisk user. Exploitation evidence was first observed by the Shadowserver Foundation on 2026-09-09.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-89026 since 09/10/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1202.

By approaching the search of inurl:pbxapi/index.php it is possible to find vulnerable targets with Google Hacking.

Applying the patch b97dbaf0b71c1c36f841e672b664afbeb02773bd is able to eliminate this problem.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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• Issabel

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• Framework

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