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Net\Application · Rrwo

CVE-2026-49942

HIGH · 7.3 CVSS v3.1 Published 2026-06-04
Fix available
A fix is available. Upgrade to 0.21 or later.
See remediation →
82/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The Net::CIDR::Set Perl module through version 0.20 fails to properly validate network masks in the mask portion of CIDR notation. It accepts Unicode digits (such as Arabic-Indic numeral U+0661) and non-digit characters, which are silently ignored, allowing network masks to be interpreted as smaller than intended and accepting larger networks. Additionally, leading zeros are accepted and treated as decimal rather than octal, causing ambiguity in what networks are permitted.

MitigationUpgrade to a patched version of Net::CIDR::Set that implements strict network mask validation using only standard decimal digits (0-9) and correctly handles leading zeros to prevent ambiguity.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Net\Application
Affected:< 0.21

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed version of Net::CIDR::Set
    Run 'perl -MNet::CIDR::Set -e 'print $Net::CIDR::Set::VERSION' or check your Perl library directory for the version file
    Affected if Version is below 0.21 (e.g., 0.20 or earlier)
  2. Test Unicode digit acceptance in network masks
    Attempt to create a Net::CIDR::Set object using a Unicode digit like U+0661 (Arabic-Indic One) in the network mask, e.g., '١.١.١.١' or in CIDR notation with Unicode digits
    Affected if The module accepts Unicode digits in network masks without error or rejection
  3. Test non-digit character handling in network masks
    Attempt to create a network mask containing non-digit characters (e.g., '10a.10b.10c.10') and observe if they are silently ignored rather than rejected
    Affected if Non-digit characters in network masks are silently accepted and ignored without warning or error
  4. Test leading zero interpretation in network masks
    Create a network with leading zeros (e.g., '010.010.010.010' or '08' in octet) and observe if it is treated as decimal rather than producing an error or being interpreted as octal
    Affected if Leading zeros are accepted and treated as decimal values without clarification or error

Environment is affected if Net::CIDR::Set version is below 0.21 AND the application processes network masks from untrusted input without additional validation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 0.21 or later
Fixed in 0.21
Interim mitigation

Upgrade to a patched version of Net::CIDR::Set that implements strict network mask validation using only standard decimal digits (0-9) and correctly handles leading zeros to prevent ambiguity.

Recommended fix High confidence

0.21

  1. Update the Net::CIDR::Set Perl module to version 0.21 or later using your Perl module management tool (e.g., 'cpan -i Net::CIDR::Set' or 'cpanm Net::CIDR::Set')
  2. If using a system package manager that ships Perl modules, update via that package manager (e.g., apt-get, yum, etc.)
  3. Verify the installed version is 0.21 or later by running 'perl -MNet::CIDR::Set -e "print $Net::CIDR::Set::VERSION"'

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Net\ Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,980
Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-49942 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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