CVE-2026-66842: BIG-IP and BIG-IQ Configuration utility vulnerability

Published Sep 2, 2026
·
Updated

BIG-IP has a vulnerability where an authenticated user of any role may be able to create administrative user accounts through an undisclosed request to Traffic Management User Interface (TMUI).

Impact:

This vulnerability may allow an authenticated attacker with network access to the BIG-IP management interface to escalate privileges by creating administrative accounts on the BIG-IP system. There is no data plane exposure; this is a control plane issue only.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected Software

1 affected component
F5 BIG-IP

Event History

Sep 2, 2026
CVE Published
via MITRE·03:40 PM
Data Sourced
via MITRE·03:40 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

Who is exposed to this issue?

BIG-IP systems whose management interface is reachable over the network are exposed if an attacker can authenticate to TMUI with any user role. The issue affects the control plane only; there is no data plane exposure described.

2

What does an attacker need to exploit it?

An attacker needs network access to the BIG-IP management interface and valid credentials for an authenticated TMUI user account. No user interaction is required, and even non-administrative roles may be sufficient.

3

What is the likely impact of successful exploitation?

An attacker may create administrative user accounts on the BIG-IP system, allowing privilege escalation to administrative access. The reported impact includes high confidentiality, integrity, and availability impact.

4

Are end-of-support BIG-IP versions covered by the evaluation?

No. Software versions that have reached End of Technical Support are not evaluated.

Contact

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