# CVE-2026-42781: F5 BIG-IP resource exhaustion in ePVA acceleration

Source: https://junglewise.ai/threats/cve-2026-42781-f5-big-ip-resource-exhaustion-in-epva-acceleration  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-13. Updated: 2026-06-23  
License: CC BY 4.0 with a link back

CVE-2026-42781 · Severity: medium · CVSS 6.5 · Published 2026-05-13

A vulnerability in F5 BIG-IP networking appliances can allow local network traffic to overwhelm the system's processing resources. This occurs when a specific hardware acceleration feature is enabled, potentially leading to a significant slowdown or total service outage. This impact can disrupt corporate network traffic management and application delivery services.

Technologies: [F5 BIG-IP](https://junglewise.ai/threats/technologies/big-ip). Vendors: [F5](https://junglewise.ai/threats/vendors/f5).

## Quick answers

**Is CVE-2026-42781 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42781 being exploited in the wild.

**How severe is CVE-2026-42781?** Medium severity, with a CVSS score of 6.5, published 13 May 2026.

**Which products and versions are affected?** F5 BIG-IP 17.1.0 to 17.1.3.1, 17.5.0 to 17.5.1.4, 21.0.0 to 21.0.0.1, Undisclosed versions (excluding EoTS).

**Is there a fix for CVE-2026-42781?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-42781 attacked?** It is attacked from the adjacent network, in a network appliance.

**Am I affected by CVE-2026-42781?** Check whether you run F5 BIG-IP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A resource exhaustion vulnerability exists in F5 BIG-IP systems when embedded Packet Velocity Acceleration (ePVA) is configured. The flaw is triggered by undisclosed local ethernet traffic, which causes an infinite loop (CWE-835) or similar condition leading to increased resource utilization in both the ePVA hardware and the Traffic Management Microkernel (TMM). An attacker on the adjacent network can exploit this to cause a denial-of-service (DoS) condition. The issue affects multiple BIG-IP modules across rSeries and VELOS platforms. Patches are available in updated versions (e.g., 17.1.3.1, 17.5.1.4, and 21.1.0).

## Affected products

- F5 BIG-IP 17.1.0 to 17.1.3.1, 17.5.0 to 17.5.1.4, 21.0.0 to 21.0.0.1

## Timeline

- 2026-05-13: advisory: Initial advisory published by F5

## References

- [https://my.f5.com/manage/s/article/K000160862](https://my.f5.com/manage/s/article/K000160862)

## Related threats

- [F5 BIG-IP privilege escalation in TMUI](https://junglewise.ai/threats/cve-2026-66842-f5-big-ip-privilege-escalation-in-tmui)
- [F5 BIG-IP Configuration utility error message spoofing](https://junglewise.ai/threats/cve-2026-63020-f5-big-ip-configuration-utility-error-message-spoofing)
- [F5 BIG-IP denial of service in HTTP/2 profile memory management](https://junglewise.ai/threats/cve-2026-59762-f5-big-ip-denial-of-service-in-http-2-profile-memory-management)
- [F5 BIG-IP and BIG-IQ incorrect permission assignment in tmsh and iControl REST](https://junglewise.ai/threats/cve-2026-42937-f5-big-ip-and-big-iq-incorrect-permission-assignment-in-tmsh-and)
- [F5 BIG-IP Appliance mode restriction bypass via path traversal](https://junglewise.ai/threats/cve-2026-42930-f5-big-ip-appliance-mode-restriction-bypass-via-path-traversal)