CVE-2026-66842

BIG-IP and BIG-IQ Configuration utility vulnerability

State: Published
Severity: 8.7 High
Published: Sep 2, 2026
Updated: Sep 3, 2026
Reserved: Jul 29, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	8.7 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	f5
3.1	8.8 High	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	f5

Weaknesses

CWE-918 Server-Side Request Forgery (SSRF)

Affected Products

Product	Versions
BIG-IPF5	21.1.0 to before 21.1.0.1Affected 21.0.0 to before 21.0.0.3Affected 17.5.0 to before 17.5.1.8Affected 17.1.0 to before 17.1.3.4Affected
BIG-IQF5	8.4.0 to before 8.4.2.1Affected

References

https://my.f5.com/manage/s/article/K000162521vendor-advisory

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