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Fencer Vulns
medium 6.5

CVE-2026-45191 json

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

published 2026-05-10 5 mo ago modified 2026-07-24 3 mo ago also EUVD-2026-28999

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits
0
none known

Summary

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.

Patch / fix

  • STIGTSP Net::CIDR::Lite 0.24
  • libnet-cidr-lite-perl Debian 12 0.22-3~deb12u2
  • libnet-cidr-lite-perl Debian 13 0.22-3~deb13u2
  • libnet-cidr-lite-perl Debian 14 0.24-1

debian advisories DEBIAN-CVE-2026-45191

  • libnet-cidr-lite-perl Ubuntu 22.04 LTS 0.22-1ubuntu0.2
  • libnet-cidr-lite-perl Ubuntu 24.04 LTS 0.22-2ubuntu0.24.04.2
  • libnet-cidr-lite-perl Ubuntu 25.10 0.22-2ubuntu0.25.10.2
  • libnet-cidr-lite-perl Ubuntu 26.04 LTS 0.22-2ubuntu0.26.04.2
  • libnet-cidr-lite-perl Ubuntu Pro 16.04 LTS 0.21-1ubuntu0.16.04.1~esm2
  • libnet-cidr-lite-perl Ubuntu Pro 18.04 LTS 0.21-1ubuntu0.18.04.1~esm2
  • libnet-cidr-lite-perl Ubuntu Pro 20.04 LTS 0.21-2ubuntu0.1+esm2

ubuntu advisories UBUNTU-CVE-2026-45191

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • perl-Net-CIDR-Lite openSUSE Tumbleweed 0.240.0-1.1

opensuse advisories openSUSE-SU-2026:10780-1

  • perl-net-cidr-lite Alpine 3.24 0.24-r0

alpine advisories ALPINE-CVE-2026-45191

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-45191 updated cvss 6.5

perl-Net-CIDR-Lite: Net::CIDR::Lite: IP ACL bypass due to improper CIDR mask validation

  • Red Hat Enterprise Linux 9 perl-Net-CIDR-Lite
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Affected products

  • STIGTSP Net::CIDR::Lite

Classification

Weakness
  • CWE-1289 Improper Validation of Unsafe Equivalence in Input

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.