Vulnerability · Published Sep 2, 2026 · Assigned by f5

CVE-2026-63020BIG-IP Configuration utility vulnerability

Low 3.1

In plain English

A low-severity security flaw in BIG-IP from F5. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities).

Severity (CVSS 3.1)3.1Low

Exploit odds (30 days)0.2%top 86.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

A vulnerability exists in an undisclosed BIG-IP Configuration utility page that may allow an attacker to spoof error messages Impact: An attacker may trick authenticated BIG-IP users into accessing malicious links and reflect a spoofed error message in the victim's BIG-IP Configuration utility web browser session. This is a control plane issue; there is no data plane exposure. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected products (as reported)

Vendor	Product	Versions
F5	BIG-IP	21.1.0 – before 21.1.0.121.0.0 – before 21.0.0.317.5.0 – before 17.5.1.817.1.0 – before 17.1.3.4

Weakness: CWE-451 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N

References

https://my.f5.com/manage/s/article/K000161728 vendor-advisory