CVE-2026-40435 PUBLISHED

BIG-IP httpd access control vulnerability

Assigner: f5
Reserved: 30.04.2026 Published: 13.05.2026 Updated: 13.05.2026

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.

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS Score: 5.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	None

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 6.9

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	Low	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	F5
Product	BIG-IP
Versions	Default: unknown unaffected from 21.0.0 to * (excl.) affected from 17.5.0 to 17.5.1.4 (excl.) affected from 17.1.0 to 17.1.3.1 (excl.) affected from 16.1.0 to * (excl.)

Credits

F5 finder

References

https://my.f5.com/manage/s/article/K000156604

Problem Types

CWE-420: Unprotected Alternate Channel CWE