Vulnerability · Published Jun 4, 2026 · Assigned by CPANSec
CVE-2026-49940Net::CIDR::Set versions through 0.20 for Perl accept non-ASCII IP addresses and netmasks
Medium 6.5
In plain English
A medium-severity security flaw in Net::CIDR::Set from RRWO. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.2%top 90.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libnet-cidr-set-perl | no fix listed | DEBIAN-CVE-2026-49940 |
| Debian:13 | libnet-cidr-set-perl | 0.15-1+deb13u1 | DEBIAN-CVE-2026-49940 |
| Debian:14 | libnet-cidr-set-perl | 0.21-1 | DEBIAN-CVE-2026-49940 |
| Ubuntu:22.04:LTS | libnet-cidr-set-perl | no fix listed | UBUNTU-CVE-2026-49940 |
| Ubuntu:24.04:LTS | libnet-cidr-set-perl | no fix listed | UBUNTU-CVE-2026-49940 |
| Ubuntu:25.10 | libnet-cidr-set-perl | no fix listed | UBUNTU-CVE-2026-49940 |
| Ubuntu:26.04:LTS | libnet-cidr-set-perl | no fix listed | UBUNTU-CVE-2026-49940 |
| Ubuntu:26.10 | libnet-cidr-set-perl | no fix listed | UBUNTU-CVE-2026-49940 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| RRWO | Net::CIDR::Set | 0 – through 0.20 |
Weakness: CWE-1289 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N