BIG-IP
CVE-2026-42919: F5 BIG-IP Appliance Mode Vulnerability
A vulnerability exists in BIG-IP systems that may allow an authenticated attacker with administrative access to escalate their privileges.
Published
ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityHIGHCVSS 4.0 7.1
EPSS0.42%Chance of exploitation in 30 days
Public exploitNot tracked
FixAvailable
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| BIG-IP 21.1 | Not affected |
| BIG-IP 21.0 | 21.0.0.1 or later |
| BIG-IP 17.5 | 17.5.1.4 or later |
| BIG-IP 17.1 | 17.1.3.1 or later |
| BIG-IP 16.1 | * or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A vulnerability exists in BIG-IP systems that may allow an authenticated attacker with administrative access to escalate their privileges. A successful exploit may allow the attacker to cross a security boundary.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 12 Oct 2026.