CVE-2025-53521 CRITICAL

CVE-2025-53521: BigIP APM Vulnerability

Vendor F5
Product BIG-IP
Weakness CWE-121
KEV Status Known Exploited
Published October 15, 2025
Last update March 31, 2026
View on NVD All CVEs

CVSS base score

9.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

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.

CISA mandated remediation

02CISA Required Action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Key dates

03Disclosure timeline

October 15, 2025 CVE published
March 31, 2026 Record updated