SB2026051441 - IP-based access restrictions bypass in BIG-IP httpd
Published: May 14, 2026
Security Bulletin ID
SB2026051441
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Information disclosure
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Unprotected Alternate Channel (CVE-ID: CVE-2026-40435)
The vulnerability allows a remote attacker to connect to the BIG-IP control plane HTTP services from blocked addresses.
The vulnerability exists due to unprotected alternate channel in httpd access control when handling requests to endpoints not covered by configured IP-based access restrictions. A remote attacker can send requests to exposed endpoints to connect to the BIG-IP control plane HTTP services from blocked addresses.
Valid login credentials are still required to interact with the BIG-IP system, and there is no data plane exposure.
Remediation
Install update from vendor's website.