IP ACL bypass via unsafe address equivalence
Published May 10, 2026 · Updated May 10, 2026
Improper IP address validation in Net::CIDR::Lite before 0.24 allows attackers to bypass IP access controls with crafted inputs. The add, _pack_ipv4, and _pack_ipv6 parsers accept trailing newlines or Unicode digits, then pack or numerically coerce them into addresses different from the supplied text. Any application that relies on find() or bin_find() for an IP allowlist or denylist can therefore match or reject the wrong address without authentication or user interaction.
Summary
What happened
Improper IP address validation in Net::CIDR::Lite before 0.24 allows attackers to bypass IP access controls with crafted inputs. The add, _pack_ipv4, and _pack_ipv6 parsers accept trailing newlines or Unicode digits, then pack or numerically coerce them into addresses different from the supplied text. Any application that relies on find() or bin_find() for an IP allowlist or denylist can therefore match or reject the wrong address without authentication or user interaction.
The record
- CVE
- CVE-2026-45190
- Published
- May 10, 2026
- Updated
- May 10, 2026
- Vendor
- Stig Palmquist
- Product
- Net::CIDR::Lite
- Classifications
- CWE-1289
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 10, 2026CVE publishedPublication date reported by the CVE source.
- May 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <0.24
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- CPANSec malformed IPv6 lookup demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo