- 1. CVE-2025-53521 – Active F5 BIG-IP Denial of Service
In this brief
1. CVE-2025-53521 – Active F5 BIG-IP Denial of Service
WhatAn actively exploited vulnerability (CVSS 7.5) in F5 BIG-IP when an APM Access Policy is configured. Allows remote denial of service without authentication.
SourceGreenbone March 2026 Threat Report [External: www.greenbone.net]
Applies toAny organisation using F5 BIG-IP with APM Access Policy
Why it mattersActively exploited in the wild, CISA listed; immediate patching required.
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