High 8.8Published Sep 2, 2026

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

Updated under an hour ago (2026-10-19 05:50 UTC)

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It affects F5 BIG-IP and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for F5 BIG-IP

Exploited in the last 30 days

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.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-918
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: f5
NVD analysis: Undergoing Analysis
Record last updated: Sep 3, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

F5 BIG-IP f5:big_ip (from the name)	from 21.1.0 before 21.1.0.1; from 21.0.0 before 21.0.0.3; from 17.5.0 before 17.5.1.8; from 17.1.0 before 17.1.3.4	CNA record
F5 BIG-IQ f5:big_iq (from the name)	from 8.4.0 before 8.4.2.1	CNA record

References

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

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.