CVE-2025-53521

critical F5 ⚠️ CISA KEV — Exploited in the Wild
CVSS v3 Base Score
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score
19.9%
Exploitation probability in 30 days
Top 5% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Published: October 15, 2025 (210 days ago)
Last Modified: March 31, 2026
Vendor: F5
Source: NVD

⚠️ CISA Known Exploited Vulnerability

Added to KEV: 2026-03-27
Remediation Due: 2026-03-30 (⚠ 45d overdue)

Description

When a BIG-IP APM access policy is configured on a virtual server, specific malicious traffic can lead to Remote Code Execution (RCE).   Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CWE

CWE-121

Affected Products

f5 big-ip access policy manager

References

🔗 my.f5.com 🔗 www.cisa.gov