Answer in brief
CVE-2026-66842 records a Unknown severity vulnerability in BIG-IP and BIG-IQ Configuration utility vulnerability. The current sources do not mark it as known exploited. The current feed maps F5/BIG-IP (generic), F5/BIG-IQ (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps F5/BIG-IP (generic), F5/BIG-IQ (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| F5/BIG-IPgeneric | >=21.1.0 <21.1.0.1 || >=21.0.0 <21.0.0.3 || >=17.5.0 <17.5.1.8 || >=17.1.0 <17.1.3.4 | 21.1.0.1, 21.0.0.3, 17.5.1.8, 17.1.3.4 |
| F5/BIG-IQgeneric | >=8.4.0 <8.4.2.1 | 8.4.2.1 |
Published upstream
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 2, 2026
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.
Quoted source text, attributed separately from HOL analysis.