CVE-2025-53856 TMM vulnerability

High 8.7 Published 15 Oct 2025 Updated 26 Feb 2026

Attackers can cause a denial of service on F5 BIG-IP devices using ePVA by sending undisclosed traffic to virtual servers or NAT objects.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-53856?

CVE-2025-53856 is a high-severity denial of service 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 virtual server, network address translation (NAT) object, or secure network address translation (SNAT) object uses the embedded Packet Velocity Acceleration (ePVA) feature, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. To determine which BIG-IP platforms have an ePVA chip refer to K12837: Overview of the ePVA feature https://my.f5.com/manage/s/article/K12837 . Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-705

Which versions are affected by CVE-2025-53856?

It affects 21 products.

Products include F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager, F5 Big-Ip Advanced Web Application Firewall, F5 Big-Ip Analytics, F5 Big-Ip Application Acceleration Manager, F5 Big-Ip Application Security Manager and 15 more.

How do I fix CVE-2025-53856?

No fix has been published for CVE-2025-53856 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-53856 being exploited?

There is no known exploitation of CVE-2025-53856 in the wild and no public exploit code.

All F5 Big-Ip Access Policy Manager vulnerabilities

Sources

Also known as GHSA-m5hq-gxg5-5f9x.