CVE-2026-40435

BIG-IP httpd access control vulnerability

Medium6.9EPSS 0.23%

Published: 13 May 2026
Updated: 13 May 2026
Reserved: 30 Apr 2026
Assigned by: f5

Description

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.

Scores

CVSS scores of CVE-2026-40435, by who scored it
Scored by	CVSS	Score	Vector
f5CNA (assigner)	4.0	Medium6.9	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
f5CNA (assigner)	3.1	Medium5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVDNVD · Analyzed	4.0	Medium6.9	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS (exploitation in 30 days): 0.23% · top 86% of all CVEs (5 Nov 2026)
CISA SSVC: Exploitation: none · Automatable: yes · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.9.

Weakness

CWE-420: Unprotected Alternate Channel (opens in a new tab)All about CWE-420 and its CVEs

Affected products

F5 · BIG-IP
- unaffected 21.0.0 – < *
- affected 17.5.0 – < 17.5.1.4
- affected 17.1.0 – < 17.1.3.1
- affected 16.1.0 – < *

References (1)

https://my.f5.com/manage/s/article/K000156604 (opens in a new tab)vendor-advisorypatch

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

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Record last updated 13 May 2026, 16:17 UTC.