Over 14,000 F5 BIG-IP APM instances remain exposed online, as attackers actively exploit a critical remote code execution flaw CVE-2025-53521. Over 14,000 F5 BIG-IP APM instances remain exposed online, with attackers actively exploiting the critical remote code execution vulnerability CVE-2025-53521 (CVSS ver. 3.1 score of 9.8), the nonprofit security organization Shadowserver warns. The vulnerability in BIG-IP […]

F5 BIG-IP APM flaw CVE-2025-53521 escalates to critical 9.8 RCE, actively exploited. Patch now, check IoCs, and secure vulnerable systems immediately.

CVE-2025-53521 was initially disclosed in October as a high-severity denial-of-service (DoS) flaw, but new information has revealed the bug is actually much more dangerous.

CVE-2025-53521 was initially disclosed in October as a high-severity denial-of-service (DoS) flaw, but new information has revealed the bug is actually much more dangerous.

A critical unauthenticated remote code execution vulnerability (CVE-2025-53521) in F5’s BIG-IP Access Policy Manager (APM) solution is under active exploitation, the US Cybersecurity and Infrastructure Security Agency warned on Friday. CISA added the flaw to its Known Exploited Vulnerabilities catalog after F5 updated the related security advisory, The advisory was initially published on October 15, 2025, when F5 confirmed a data breach that resulted in a “highly sophisticated nation-state threat actor” accessing – among other … More → The post Attackers are exploiting RCE vulnerability in BIG-IP APM systems (CVE-2025-53521) appeared first on Help Net Security .

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds a flaw in F5 BIG-IP AMP to its Known Exploited Vulnerabilities catalog. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added a flaw in F5 BIG-IP AMP, tracked as CVE-2025-53521 (CVSS ver. 3.1 score of 9.8), to its Known Exploited Vulnerabilities (KEV) catalog. The vulnerability in BIG-IP APM allows […]