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

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-13 · updated 2026-10-26
Weakness: CWE-835

Description

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 products

F5 BIG-IP APM: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
BIG-IP: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Advanced Web Application Firewall: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Analytics: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Networks, Inc. BIG-IP (AAM): from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
BIG-IP ASM: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Application Visibility And Reporting: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Automation Toolchain: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Carrier-Grade Nat: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 BIG-IP Container Ingress Services: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Ddos Hybrid Defender: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 BIG-IP DNS: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Edge Gateway: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Fraud Protection Service: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Global Traffic Manager: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Link Controller: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 BIG-IP (LTM): from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Networks, Inc. BIG-IP (PEM): from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Ssl Orchestrator: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Webaccelerator: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0
F5 Big-Ip Websafe: from 17.1.0 through 17.1.3; from 17.5.0 through 17.5.1; 21.0.0

References

https://my.f5.com/manage/s/article/K000160862

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