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CVE-2026-49940 RRWO CVE debrief

CVE-2026-49940 is a vulnerability in Net::CIDR::Set versions through 0.20 for Perl. The issue allows non-ASCII IP addresses and netmasks to be accepted but not properly parsed as numbers. This could allow network masks to accept larger networks. The vulnerability has a CVSS score of 6.5 and a severity of MEDIUM.

Vendor
RRWO
Product
Net::CIDR::Set
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-04
Original CVE updated
2026-06-08
Advisory published
2026-06-04
Advisory updated
2026-06-08

Who should care

Users of Net::CIDR::Set versions through 0.20 for Perl should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability is caused by the acceptance of non-ASCII IP addresses and netmasks, which are not properly parsed as numbers. This could allow network masks to accept larger networks.

Defensive priority

MEDIUM

Recommended defensive actions

  • Update to version 0.21 or later of Net::CIDR::Set
  • Use ASCII IP addresses and netmasks

Evidence notes

The vulnerability was reported by Rrwo and has been documented in the NVD.

Official resources

CVE-2026-49940 was published on 2026-06-04T17:16:33.053Z and modified on 2026-06-08T16:35:43.660Z.