BIG-IP
CVE-2026-40435: BIG-IP httpd access control vulnerability
When configured, IP-based access restrictions for httpd do not cover all endpoints, which may allow connections from blocked addresses.
Published
ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityMEDIUMCVSS 4.0 6.9
EPSS0.31%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 21.0 | Not affected |
| 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
When configured, IP-based access restrictions for httpd do not cover all endpoints, which may allow connections from blocked addresses. 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.