Vulnerability · Published May 10, 2026 · Assigned by CPANSec

CVE-2026-45191Net::CIDR::Lite versions before 0.24 for Perl does not properly consider extraneous zero characters in CIDR mask values, which may allow IP ACL bypass

Medium 6.5

In plain English

A medium-severity security flaw in Net::CIDR::Lite from STIGTSP. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 77.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Net::CIDR::Lite versions before 0.24 for Perl does not properly consider extraneous zero characters in CIDR mask values, which may allow IP ACL bypass. Mask forms like "/00" and "/01" pass validation and parse to the same prefix as their unpadded value. See also CVE-2026-45190.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.24perl-net-cidr-lite0.24-r0ALPINE-CVE-2026-45191
Debian:12libnet-cidr-lite-perl0.22-3~deb12u2DEBIAN-CVE-2026-45191
Debian:13libnet-cidr-lite-perl0.22-3~deb13u2DEBIAN-CVE-2026-45191
Debian:14libnet-cidr-lite-perl0.24-1DEBIAN-CVE-2026-45191
Ubuntu:22.04:LTSlibnet-cidr-lite-perl0.22-1ubuntu0.2USN-8453-1
Ubuntu:22.04:LTSlibnet-cidr-lite-perl0.22-1ubuntu0.2UBUNTU-CVE-2026-45191
Ubuntu:24.04:LTSlibnet-cidr-lite-perl0.22-2ubuntu0.24.04.2USN-8453-1
Ubuntu:24.04:LTSlibnet-cidr-lite-perl0.22-2ubuntu0.24.04.2UBUNTU-CVE-2026-45191
Ubuntu:25.10libnet-cidr-lite-perl0.22-2ubuntu0.25.10.2USN-8453-1
Ubuntu:25.10libnet-cidr-lite-perl0.22-2ubuntu0.25.10.2UBUNTU-CVE-2026-45191
Ubuntu:26.04:LTSlibnet-cidr-lite-perl0.22-2ubuntu0.26.04.2UBUNTU-CVE-2026-45191
Ubuntu:26.04:LTSlibnet-cidr-lite-perl0.22-2ubuntu0.26.04.2USN-8453-1

Affected products (as reported)

VendorProductVersions
STIGTSP Net::CIDR::Lite 0 – before 0.24

Weakness: CWE-1289 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

References