IP Deny Rule Misconfiguration in BusyBox httpd
CVE-2026-88831

5.3MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Hardened Images
Vendor
CVE Published:
23 September 2026

What is CVE-2026-88831?

The BusyBox httpd software exposes a vulnerability where invalid CIDR prefix lengths in IP deny rules result in a misconfiguration, allowing the rule to fail open. This occurs when a parsed IP address has a zeroed mask, causing it to match no clients, potentially bypassing intended access controls. This flaw emphasizes the importance of validating CIDR inputs to ensure proper firewall configuration.

References

https://access.redhat.com/security/cve/CVE-2026-88831
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2531346
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.