CVE-2026-89026: Issabel Foundation Issabel Framework

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

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.

Affected products

Published 2026-09-15. Last modified 2026-09-24.