# CVE-2026-66842

## Summary

- **CVE ID:** CVE-2026-66842
- **Severity:** HIGH
- **CVSS Score:** 8.8 (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)
- **CWE:** CWE-918
- **Published:** Sep 2, 2026
- **Last Modified:** Sep 3, 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.

## Affected Products

- F5 — BIG-IP (21.1.0)
- F5 — BIG-IP (21.0.0)
- F5 — BIG-IP (17.5.0)
- F5 — BIG-IP (17.1.0)
- F5 — BIG-IQ (8.4.0)

## References

- [CNA](https://my.f5.com/manage/s/article/K000162521)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.28%
- **EPSS Percentile:** 20.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._