Net::CIDR::Set: Improper Validation of Unsafe Equivalence in Input
CVE-2026-49942 is a high-severity improper validation of unsafe equivalence in input vulnerability in Net::CIDR::Set from RRWO, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Net::CIDR::Set versions: 0.20 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Net to 0.21 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| RRWO | Net::CIDR::Set | 0.20 and earlier | Not stated |
| Rrwo | Net | before 0.21 | 0.21 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. Scored by CISA (ADP).
Official description
Net::CIDR::Set versions through 0.20 for Perl did not validate network masks. The mask portion of a network mask could contain Unicode digits such as the Arabic-Indic One (U+0661), or non-digits, which were ignored. This could allow network masks to accept larger networks. Leading zeros were also accepted, but treated as decimal instead of octal. This could lead to confusion about what networks are acceptable.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Validation of Unsafe Equivalence in Input
The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.
More Improper Validation of Unsafe Equivalence in Input vulnerabilities (CWE-1289)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- metacpan.org/release/RRWO/Net-CIDR-Set-0.21/changesRelease Notes
Third-party and government advisories
- nvd.nist.gov/vuln/detail/CVE-2025-40911Third Party Advisory, US Government Resource
- nvd.nist.gov/vuln/detail/CVE-2026-45191Third Party Advisory, US Government Resource
Other vulnerabilities in Net::CIDR::Set
- 7.5 High severity
- 7.5 High severity
Recent Improper Validation of Unsafe Equivalence in Input vulnerabilities
- 8.2 High severity
- 7.1 High severity
- 7.2 High severity
- 7.8 High severity
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