CVE-2021-22976: F5 BIG-IP Advanced Web Application Firewall

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

On BIG-IP Advanced WAF and ASM version 16.0.x before 16.0.1.1, 15.1.x before 15.1.2, 14.1.x before 14.1.3.1, 13.1.x before 13.1.3.6, and all 12.1.x versions, when the BIG-IP ASM system processes WebSocket requests with JSON payloads, an unusually large number of parameters can cause excessive CPU usage in the BIG-IP ASM bd process. Note: Software versions which have reached End of Software Development (EoSD) are not evaluated.

Affected products

• F5 BIG-IP Advanced Web Application Firewall: from 12.1.0, up to and including 12.1.5; from 13.1.0, before 13.1.3.6 (fixed in 13.1.3.6); from 14.1.0, before 14.1.3.1 (fixed in 14.1.3.1); from 15.1.0, before 15.1.2 (fixed in 15.1.2); from 16.0.0, before 16.0.1.1 (fixed in 16.0.1.1)
• F5 BIG-IP Application Security Manager: from 12.1.0, up to and including 12.1.5; from 13.1.0, before 13.1.3.6 (fixed in 13.1.3.6); from 14.1.0, before 14.1.3.1 (fixed in 14.1.3.1); from 15.1.0, before 15.1.2 (fixed in 15.1.2); from 16.0.0, before 16.0.1.1 (fixed in 16.0.1.1)

Published 2021-02-12. Last modified 2026-06-17.