GHSA-C25Q-MQX5-M6V8
Vulnerability from github – Published: 2026-04-11 00:31 – Updated: 2026-04-13 15:31Net::CIDR::Lite versions before 0.23 for Perl does not validate IPv6 group count, which may allow IP ACL bypass.
_pack_ipv6() does not check that uncompressed IPv6 addresses (without ::) have exactly 8 hex groups. Inputs like "abcd", "1:2:3", or "1:2:3:4:5:6:7" are accepted and produce packed values of wrong length (3, 7, or 15 bytes instead of 17).
The packed values are used internally for mask and comparison operations. find() and bin_find() use Perl string comparison (lt/gt) on these values, and comparing strings of different lengths gives wrong results. This can cause find() to incorrectly report an address as inside or outside a range.
Example:
my $cidr = Net::CIDR::Lite->new("::/8"); $cidr->find("1:2:3"); # invalid input, incorrectly returns true
This is the same class of input validation issue as CVE-2021-47154 (IPv4 leading zeros) previously fixed in this module.
See also CVE-2026-40199, a related issue in the same function affecting IPv4 mapped IPv6 addresses.
{
"affected": [],
"aliases": [
"CVE-2026-40198"
],
"database_specific": {
"cwe_ids": [
"CWE-1286"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-10T22:16:21Z",
"severity": "HIGH"
},
"details": "Net::CIDR::Lite versions before 0.23 for Perl does not validate IPv6 group count, which may allow IP ACL bypass.\n\n_pack_ipv6() does not check that uncompressed IPv6 addresses (without ::) have exactly 8 hex groups. Inputs like \"abcd\", \"1:2:3\", or \"1:2:3:4:5:6:7\" are accepted and produce packed values of wrong length (3, 7, or 15 bytes instead of 17).\n\nThe packed values are used internally for mask and comparison operations. find() and bin_find() use Perl string comparison (lt/gt) on these values, and comparing strings of different lengths gives wrong results. This can cause find() to incorrectly report an address as inside or outside a range.\n\nExample:\n\n my $cidr = Net::CIDR::Lite-\u003enew(\"::/8\");\n $cidr-\u003efind(\"1:2:3\"); # invalid input, incorrectly returns true\n\nThis is the same class of input validation issue as CVE-2021-47154 (IPv4 leading zeros) previously fixed in this module.\n\nSee also CVE-2026-40199, a related issue in the same function affecting IPv4 mapped IPv6 addresses.",
"id": "GHSA-c25q-mqx5-m6v8",
"modified": "2026-04-13T15:31:36Z",
"published": "2026-04-11T00:31:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40198"
},
{
"type": "WEB",
"url": "https://github.com/stigtsp/Net-CIDR-Lite/commit/25d65f85dbe4885959a10471725ec9d250a589c3.patch"
},
{
"type": "WEB",
"url": "https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.23/changes"
},
{
"type": "WEB",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-40199"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.