CVE detail
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.
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 13.9 · diversity 15.0 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 0
- within the 30d window
- Peak daily
- 0
- highest bucket
Evidence
Source links by recency
3 source links · newest first
No excerpt available.
Third Party Advisorywww.cve.orgApr 10, 2026, 10:16 PMNo excerpt available.
Release Notesmetacpan.orgApr 10, 2026, 10:16 PM- https://github.com/stigtsp/Net-CIDR-Lite/commit/b7166b1fa17b3b14b4c795ace5b3fbf71a0bd04a.patchgithub.com
No excerpt available.
Exploitgithub.comApr 10, 2026, 10:16 PM
Exploit code
Public exploit repository references
Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.
0 repository references · best confidence N/A · max 0 stars
Related records
Similar CVEs
6 related CVEs with shared weakness or product evidence
- CVE-2026-62424CVSS 5.5 · Medium
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The directory and Rock Ridge / SUSP walk in libfs…
- CVE-2026-62423CVSS 5.5 · Medium
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The directory and Rock Ridge / SUSP walk in libfs…
- CVE-2026-26081CVSS 4.8 · Medium
HAProxy Community Edition 3.0 through 3.3 before 3.3.3 lacks a length check for the NEW_TOKEN format. HAProxy Enterprise and ALOHA are also affected.
- CVE-2026-54466CVSS 9.2 · Critical
websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.7.5, the frame format in draft versions of the WebSocket protocol includes a length header that all…
- CVE-2026-48487CVSS 5.3 · Medium
Zeroconf is a pure Python implementation of multicast DNS service discovery. Prior to 0.149.16, _read_character_string and _read_string in src/zeroconf/_protocol/incoming.py advan…
- CVE-2026-60060CVSS 5.1 · Medium
Improper Handling of Length Parameter Inconsistency (CWE-130) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish…