# CVE-2026-34019: F5 BIG-IP denial of service in BFD routing protocols

Source: https://junglewise.ai/threats/cve-2026-34019-f5-big-ip-denial-of-service-in-bfd-routing-protocols  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-13. Updated: 2026-06-29  
License: CC BY 4.0 with a link back

CVE-2026-34019 · Severity: medium · CVSS 5.3 · Published 2026-05-13

F5 BIG-IP devices, which manage and secure enterprise network traffic, are vulnerable to a denial-of-service issue when using certain routing protocols. An attacker can send specific network traffic that causes the device to stop processing health-check signals, leading to an unexpected network failover. This can result in temporary service disruptions or instability in how the network routes user traffic.

Technologies: [F5 BIG-IP](https://junglewise.ai/threats/technologies/big-ip), [F5 Big-Ip Access Policy Manager](https://junglewise.ai/threats/technologies/big-ip-access-policy-manager), [F5 Big-Ip Advanced Firewall Manager](https://junglewise.ai/threats/technologies/big-ip-advanced-firewall-manager), [F5 Big-Ip Local Traffic Manager](https://junglewise.ai/threats/technologies/big-ip-local-traffic-manager). Vendors: [F5](https://junglewise.ai/threats/vendors/f5).

## Quick answers

**Is CVE-2026-34019 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34019 being exploited in the wild.

**How severe is CVE-2026-34019?** Medium severity, with a CVSS score of 5.3, published 13 May 2026.

**Which products and versions are affected?** F5 BIG-IP Not specified (EoTS versions excluded); F5 Big-Ip Access Policy Manager 16.1.0 - 16.1.6, 17.1.0 - 17.1.2, 17.5.0; F5 Big-Ip Advanced Firewall Manager 16.1.0 - 16.1.6, 17.1.0 - 17.1.2, 17.5.0; F5 Big-Ip Global Traffic Manager 16.1.0 - 16.1.6, 17.1.0 - 17.1.2, 17.5.0; and 1 more.

**Is there a fix for CVE-2026-34019?** 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-2026-34019 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-34019?** Check whether you run F5 BIG-IP, F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager or one of the others listed 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 vulnerability exists in the F5 BIG-IP Traffic Management Microkernel (TMM) related to the handling of Bidirectional Forwarding Detection (BFD) packets. When BFD is enabled for static or dynamic routing protocols, undisclosed network traffic can trigger a condition where TMM stops processing BFD packets. This leads to a timeout in the BFD session, causing the associated routing protocols to incorrectly assume a link failure and initiate a failover. The vulnerability is classified as CWE-410 (Insufficient Resource Pool) and can be exploited by a remote, unauthenticated attacker. Fixed versions include 17.5.1 and 17.1.2-ENG, while version 21.0.0 is reported as unaffected.

## Affected products

- F5 BIG-IP Access Policy Manager 16.1.0 - 16.1.6, 17.1.0 - 17.1.2, 17.5.0
- F5 BIG-IP Advanced Firewall Manager 16.1.0 - 16.1.6, 17.1.0 - 17.1.2, 17.5.0
- F5 BIG-IP Local Traffic Manager 16.1.0 - 16.1.6, 17.1.0 - 17.1.2, 17.5.0
- F5 BIG-IP Global Traffic Manager 16.1.0 - 16.1.6, 17.1.0 - 17.1.2, 17.5.0

## Timeline

- 2026-05-13: disclosed
- 2026-05-13: advisory

## References

- [https://my.f5.com/manage/s/article/K000150508](https://my.f5.com/manage/s/article/K000150508)

## 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)