CVE-2026-40198Disclosure(stigtsp / net\)

LOWCVSS 7.5 · HIGH

Signal is active with 4 mentions in latest observed window

Immediate actions

Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

Net::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.

stigtsp CVEs Back to dashboard

0.0/ 10 priority

Sources & remediation

Patch / fix

https://github.com/stigtsp/Net-CIDR-Lite/commit/25d65f85dbe4885959a10471725ec9d250a589c3.patch

Vendor / third-party advisories

https://www.cve.org/CVERecord?id=CVE-2026-40199

Other references

https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.23/changes

Weakness type (CWE)

CWE-1286

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

net\

Threat summary

4 mentions across 1 observed day

What's happening

Technical details provided in 4 signals
Disclosure: 4 classified signals
4 total mentions across 1 day

Affected systems

Vendors

stigtsp

Products

net\

1 version affected across 1 product

Deep dive

Activity timeline4 mentions / 1d

Signal classification1 categories

Disclosure

4100.0%

Referenced assets5 URLs

By indicator

Full discourse4 posts

Open Source Security mailing list@oss_security181d
Disclosure
Perl CPAN CVE-2026-40198: Net::CIDR::Lite before 0.23 does not validate IPv6 group count, which may allow IP ACL bypass https://www.openwall.com/lists/oss-security/2026/04/11/1 CVE-2026-40199: Net::CIDR::Lite before 0.23 mishandles IPv4 mapped IPv6 addresses, which may allow IP ACL bypass https://www.openwall.com/lists/oss-security/2026/04/11/2
Post summary
The text announces two CVEs (CVE‑2026‑40198 and CVE‑2026‑40199) affecting Net::CIDR::Lite that allow IP ACL bypass due to incorrect IPv6 handling.
00030374
4.6K followersView on X
CVE@CVEnew180d
Disclosure
CVE-2026-40198 Net::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 a… https://www.cve.org/CVERecord?id=CVE-2026-40198
Post summary
CVE‑2026‑40198 is a vulnerability in Net::CIDR::Lite versions prior to 0.23 that fails to validate IPv6 group counts, potentially allowing ACL bypass; the post provides technical details but no exploit, patch, or PoC information.
00000138
57.1K followersView on X
CyberDudeBivash® | Global Cybersecurity Company@cyberbivash180d
Disclosure
🚨 CYBERDUDEBIVASH SENTINEL APEX ALERT 🚨 Threat: CVE-2026-40198: Net::CIDR::Lite versions before 0.23 for Perl does not validate IPv6 group count, which may allow IP ACL bypass Intel Report: https://ift.tt/2bf7QmM
Post summary
The alert provides initial technical details on CVE-2026-40198 and its potential to bypass IP ACLs via malformed IPv6 group counts, but offers no evidence of exploitation, a PoC, or mitigation guidance.
0000029
280 followersView on X
Vulmon Vulnerability Feed@VulmonFeeds180d
Disclosure
CVE-2026-40198 IPv6 Group Count Validation Bypass in Net::CIDR::Lite Before 0.23 https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-40198
Post summary
The post references CVE‑2026‑40198, describing it as an IPv6 group count validation bypass in Net::CIDR::Lite before 0.23, but provides no PoC, exploit code, active exploitation evidence, or patch information.
0000050
4.0K followersView on X

CPE platform detail1 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

1 of 1 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	stigtsp	net\	\	-	-

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What researchers are saying

CVE-2026-40198

Open Source Security mailing list@oss_securityDisclosure

The text announces two CVEs (CVE‑2026‑40198 and CVE‑2026‑40199) affecting Net::CIDR::Lite that allow IP ACL bypass due to incorrect IPv6 handling.

CVE@CVEnewDisclosure

CVE‑2026‑40198 is a vulnerability in Net::CIDR::Lite versions prior to 0.23 that fails to validate IPv6 group counts, potentially allowing ACL bypass; the post provides technical details but no exploit, patch, or PoC information.

CyberDudeBivash® | Global Cybersecurity Company@cyberbivashDisclosure

The alert provides initial technical details on CVE-2026-40198 and its potential to bypass IP ACLs via malformed IPv6 group counts, but offers no evidence of exploitation, a PoC, or mitigation guidance.

Vulmon Vulnerability Feed@VulmonFeedsDisclosure

The post references CVE‑2026‑40198, describing it as an IPv6 group count validation bypass in Net::CIDR::Lite before 0.23, but provides no PoC, exploit code, active exploitation evidence, or patch information.