CVE-2026-42781: BIG-IP FastL4 virtual server vulnerability

Published May 13, 2026
·
Updated

When embedded Packet Velocity Acceleration (ePVA) acceleration is configured, undisclosed local ethernet traffic can cause an increase in ePVA and Traffic Management Microkernel (TMM) resource utilization.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected Software

64 affected components
F5 BIG-IP
F5 BIG-IP Access Policy Manager=21.0.0
F5 BIG-IP Advanced Firewall Manager=21.0.0
F5 Big-ip Advanced Web Application Firewall=21.0.0
F5 BIG-IP Analytics=21.0.0
F5 Big-ip Application Acceleration Manager=21.0.0
F5 BIG-IP Application Security Manager=21.0.0
F5 Big-ip Application Visibility And Reporting=21.0.0
F5 Big-ip Automation Toolchain=21.0.0
F5 Big-ip Carrier-grade Nat=21.0.0
F5 BIG-IP Container Ingress Services=21.0.0
F5 Big-ip Ddos Hybrid Defender=21.0.0
F5 Big-ip Domain Name System=21.0.0
F5 BIG-IP Edge Gateway=21.0.0
F5 Big-ip Fraud Protection Service=21.0.0
F5 Big-ip Global Traffic Manager=21.0.0
F5 Big-ip Link Controller=21.0.0
F5 Big-ip Local Traffic Manager=21.0.0
F5 Big-ip Policy Enforcement Manager=21.0.0
F5 BIG-IP SSL Orchestrator=21.0.0
F5 Big-ip Webaccelerator=21.0.0
F5 Big-ip Websafe=21.0.0
F5 BIG-IP Access Policy Manager>=17.1.0<=17.1.3
F5 BIG-IP Access Policy Manager>=17.5.0<=17.5.1
F5 BIG-IP Advanced Firewall Manager>=17.1.0<=17.1.3
F5 BIG-IP Advanced Firewall Manager>=17.5.0<=17.5.1
F5 Big-ip Advanced Web Application Firewall>=17.1.0<=17.1.3
F5 Big-ip Advanced Web Application Firewall>=17.5.0<=17.5.1
F5 BIG-IP Analytics>=17.1.0<=17.1.3
F5 BIG-IP Analytics>=17.5.0<=17.5.1
F5 Big-ip Application Acceleration Manager>=17.1.0<=17.1.3
F5 Big-ip Application Acceleration Manager>=17.5.0<=17.5.1
F5 BIG-IP Application Security Manager>=17.1.0<=17.1.3
F5 BIG-IP Application Security Manager>=17.5.0<=17.5.1
F5 Big-ip Application Visibility And Reporting>=17.1.0<=17.1.3
F5 Big-ip Application Visibility And Reporting>=17.5.0<=17.5.1
F5 Big-ip Automation Toolchain>=17.1.0<=17.1.3
F5 Big-ip Automation Toolchain>=17.5.0<=17.5.1
F5 Big-ip Carrier-grade Nat>=17.1.0<=17.1.3
F5 Big-ip Carrier-grade Nat>=17.5.0<=17.5.1
F5 BIG-IP Container Ingress Services>=17.1.0<=17.1.3
F5 BIG-IP Container Ingress Services>=17.5.0<=17.5.1
F5 Big-ip Ddos Hybrid Defender>=17.1.0<=17.1.3
F5 Big-ip Ddos Hybrid Defender>=17.5.0<=17.5.1
F5 Big-ip Domain Name System>=17.1.0<=17.1.3
F5 Big-ip Domain Name System>=17.5.0<=17.5.1
F5 BIG-IP Edge Gateway>=17.1.0<=17.1.3
F5 BIG-IP Edge Gateway>=17.5.0<=17.5.1
F5 Big-ip Fraud Protection Service>=17.1.0<=17.1.3
F5 Big-ip Fraud Protection Service>=17.5.0<=17.5.1
F5 Big-ip Global Traffic Manager>=17.1.0<=17.1.3
F5 Big-ip Global Traffic Manager>=17.5.0<=17.5.1
F5 Big-ip Link Controller>=17.1.0<=17.1.3
F5 Big-ip Link Controller>=17.5.0<=17.5.1
F5 Big-ip Local Traffic Manager>=17.1.0<=17.1.3
F5 Big-ip Local Traffic Manager>=17.5.0<=17.5.1
F5 Big-ip Policy Enforcement Manager>=17.1.0<=17.1.3
F5 Big-ip Policy Enforcement Manager>=17.5.0<=17.5.1
F5 BIG-IP SSL Orchestrator>=17.1.0<=17.1.3
F5 BIG-IP SSL Orchestrator>=17.5.0<=17.5.1
F5 Big-ip Webaccelerator>=17.1.0<=17.1.3
F5 Big-ip Webaccelerator>=17.5.0<=17.5.1
F5 Big-ip Websafe>=17.1.0<=17.1.3
F5 Big-ip Websafe>=17.5.0<=17.5.1

Event History

May 13, 2026
CVE Published
via MITRE·02:12 PM
Data Sourced
via MITRE·02:12 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·04:16 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-42781?

CVE-2026-42781 is classified as a medium severity vulnerability due to increased resource utilization impacting performance.

2

How do I fix CVE-2026-42781?

To remediate CVE-2026-42781, it is recommended to upgrade to the latest F5 BIG-IP software version that addresses this vulnerability.

3

What versions of F5 BIG-IP are affected by CVE-2026-42781?

CVE-2026-42781 affects specific versions of F5 BIG-IP that have embedded Packet Velocity Acceleration configured.

4

What are the potential impacts of CVE-2026-42781?

The potential impact of CVE-2026-42781 includes degraded performance due to increased ePVA and TMM resource utilization.

5

Is there a workaround for CVE-2026-42781?

Currently, there are no documented workarounds for CVE-2026-42781, and upgrading to a patched version is the recommended course of action.

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