CVE-2026-40199

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-40199
Net::CIDR::Lite versions before 0.23 for Perl mishandles IPv4 mapped IPv6 addresses, which may allow IP ACL bypass. _pack_ipv6() includes the sentinel byte from _pack_ipv4() when building the packed representation of IPv4 mapped addresses like ::ffff:192.168.1.1. This produces an 18 byte value instead of 17 bytes, misaligning the IPv4 part of the address. The wrong length causes incorrect results in mask operations (bitwise AND truncates to the shorter operand) and in find() / bin_find() which use Perl string comparison (lt/gt). This can cause find() to incorrectly match or miss addresses. Example: my $cidr = Net::CIDR::Lite->new("::ffff:192.168.1.0/120"); $cidr->find("::ffff:192.168.2.0"); # incorrectly returns true This is triggered by valid RFC 4291 IPv4 mapped addresses (::ffff:x.x.x.x). See also CVE-2026-40198, a related issue in the same function affecting malformed IPv6 addresses.

6.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References
Link Resource
https://github.com/stigtsp/Net-CIDR-Lite/commit/b7166b1fa17b3b14b4c795ace5b3fbf71a0bd04a.patch Patch
https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.23/changes Release Notes
https://www.cve.org/CVERecord?id=CVE-2026-40198 Third Party Advisory
Configurations

Configuration 1 (hide)

cpe:2.3:a:stigtsp:net\:\:cidr\:\:lite:*:*:*:*:*:perl:*:*
History

21 Apr 2026, 18:41

Type Values Removed Values Added
First Time Stigtsp
Stigtsp net\
CPE cpe:2.3:a:stigtsp:net\:\:cidr\:\:lite:*:*:*:*:*:perl:*:*
References () https://github.com/stigtsp/Net-CIDR-Lite/commit/b7166b1fa17b3b14b4c795ace5b3fbf71a0bd04a.patch - () https://github.com/stigtsp/Net-CIDR-Lite/commit/b7166b1fa17b3b14b4c795ace5b3fbf71a0bd04a.patch - Patch
References () https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.23/changes - () https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.23/changes - Release Notes
References () https://www.cve.org/CVERecord?id=CVE-2026-40198 - () https://www.cve.org/CVERecord?id=CVE-2026-40198 - Third Party Advisory

13 Apr 2026, 15:17

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 6.5

10 Apr 2026, 22:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-04-10 22:16

Updated : 2026-04-21 18:41

NVD link : CVE-2026-40199

Mitre link : CVE-2026-40199

CVE.ORG link : CVE-2026-40199

JSON object : View

Products Affected

stigtsp

  • net\
CWE
CWE-130

Improper Handling of Length Parameter Inconsistency