CVE-2026-44237
HIGHFreePBX is an open source IP PBX. Prior to 17.0.8, the FreePBX api module's OAuth2 implementation does not sufficiently validate client credentials during token issuance. Knowledge…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
FreePBX is an open source IP PBX. Prior to 17.0.8, the FreePBX api module's OAuth2 implementation does not sufficiently validate client credentials during token issuance. Knowledge of a valid client_id is required. The validateClient() method in ClientRepository.php unconditionally returns true, allowing any party with knowledge of a valid client_id to obtain OAuth2 access tokens without providing the correct client_secret. This vulnerability is fixed in 17.0.8.
Affected Products
freepbxsangomaDetection & mitigation playbook
Vendor / applianceDetect
Inventory every sangoma freepbx deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the sangoma freepbx security patch or hotfix for CVE-2026-44237 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-44237 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-44237. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-44237 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-44237 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.