CVE-2021-43405: Fusionpbx

High severity, CVSS 8.8. EPSS: 35.6% chance of exploitation in the next 30 days.

An issue was discovered in FusionPBX before 4.5.30. The fax_extension may have risky characters (it is not constrained to be numeric).

Affected products

• Fusionpbx Fusionpbx: before 4.5.30 (fixed in 4.5.30)

Published 2021-11-05. Last modified 2026-06-17.