CVE-2025-40911Network attack vector

Access-control bypass via leading-zero IPv4 quads

Published May 27, 2025 · Updated May 28, 2025

Improper IPv4 validation in Net::CIDR::Set 0.10 through 0.13 allows remote attackers to bypass IP-based access controls. The IPv4 and embedded-IPv4 packing routines accept one- to three-digit address quads without rejecting a leading zero, allowing ambiguous strings such as 010.0.0.1 into set operations. Exposure depends on consuming Perl code using attacker-supplied addresses for authorization; the upstream patch says the octal interpretation affects other modules and was not observed directly in this module.

CVSS severity6.5
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper IPv4 validation in Net::CIDR::Set 0.10 through 0.13 allows remote attackers to bypass IP-based access controls. The IPv4 and embedded-IPv4 packing routines accept one- to three-digit address quads without rejecting a leading zero, allowing ambiguous strings such as 010.0.0.1 into set operations. Exposure depends on consuming Perl code using attacker-supplied addresses for authorization; the upstream patch says the octal interpretation affects other modules and was not observed directly in this module.

The record

CVE
CVE-2025-40911
Published
May 27, 2025
Updated
May 28, 2025
Vendor
Robert Rothenberg
Product
Net::CIDR::Set
Classifications
CWE-1287
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2025CVE publishedPublication date reported by the CVE source.
  2. May 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.10 <=0.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Robert Rothenberg · Net::CIDR::Setversion=0.10 <=0.13

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1287Improper Validation of Specified Type of Input

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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