CVE-2026-49940: Net::CIDR::Set versions through 0.20 for Perl accept non-ASCII IP addresses and netmasks

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-04 · updated 2026-07-22
Weakness: CWE-1289

Description

Net::CIDR::Set versions through 0.20 for Perl accept non-ASCII IP addresses and netmasks. Unicode digits such as the Arabic-Indic One (U+0661) were accepted but not properly parsed as numbers. This could allow network masks to accept larger networks.

Affected products

RRWO Net::Cidr::Set: before 0.21 — fixed in 0.21

How to fix

Upgrade to a fixed version: RRWO Net::Cidr::Set 0.21. Check the vendor advisory for mitigations.

References

https://metacpan.org/release/RRWO/Net-CIDR-Set-0.21/changes
https://nvd.nist.gov/vuln/detail/CVE-2025-40911

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