CVE-2025-53521 F5 BIG-IP Stack-Based Buffer Overflow
Attackers can achieve remote code execution on F5 BIG-IP devices by sending malicious traffic to a configured APM access policy.
- Exploited in the wild
- Since 27 Mar 2026
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-53521?
CVE-2025-53521 is a critical memory corruption vulnerability in F5 Big-Ip Access Policy Manager, published on 15 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-121
Which versions are affected by CVE-2025-53521?
It affects 1 product.
Products include F5 Big-Ip Access Policy Manager.
How do I fix CVE-2025-53521?
No fix has been published for CVE-2025-53521 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 30 Mar 2026.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-53521 being exploited?
Yes. Attackers have exploited CVE-2025-53521 in the wild since at least 27 Mar 2026.
Other vulnerabilities in F5 Big-Ip Access Policy Manager
- CVE-2023-46747 F5 BIG-IP Configuration Utility Authentication Bypass
- CVE-2022-1388 F5 BIG-IP Missing Authentication
- CVE-2021-22986 F5 BIG-IP and BIG-IQ Centralized Management iControl REST Remote Code Execution
- CVE-2021-22991 F5 BIG-IP Traffic Management Microkernel Buffer Overflow
- CVE-2020-5902 F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution
Sources
Also known as GHSA-j3cp-7wh4-9f6c.