CVE-2026-49942 | Net::CIDR::Set versions through 0.20 for Perl did not validate network masks

Net::CIDR::Set versions through 0.20 for Perl did not validate network masks. The mask portion of a network mask could contain Unicode digits such as the Arabic-Indic One (U+0661), or non-digits, which were ignored. This could allow network masks to accept larger networks. Leading zeros were also accepted, but treated as decimal instead of octal. This could lead to confusion about what networks are acceptable.

Published: 2026-06-04 Last update: 2026-06-08 Assigner: 9b29abf9-4ab0-4765-b253-1875cd9b441e Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-49942 is rated Moderate Risk (42.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.49%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-49942

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.04% 0.49% +0.45%
2 2026-06-09 0.05% 0.04% -0.01%
3 2026-06-05 — 0.05% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-49942

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 3.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-49942

GitHub Security Advisory for CVE-2026-49942

GHSA-fff7-gx98-vr3g · Severity: high — Net::CIDR::Set versions through 0.20 for Perl did not validate network masks. The mask portion...

OS Trackers for CVE-2026-49942

vendor priority summary link
debian not yet assigned CVE-2026-49942 not yet assigned priority: Debian including 1 source packages (libnet-cidr-set-perl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-49942
ubuntu medium CVE-2026-49942 medium priority: Ubuntu including 1 source packages (libnet-cidr-set-perl), 6 status rows across 6 suites (focal, jammy, noble, questing, resolute, upstream): needs-triage 5, released 1. https://ubuntu.com/security/CVE-2026-49942

Affected software / configurations for CVE-2026-49942

Vendor Product Version Raw CPE
rrwo net::cidr::set < 0.21 cpe:2.3:a:rrwo:net\:\:cidr\:\:set:*:*:*:*:*:perl:*:*

References for CVE-2026-49942

URL Tags
https://metacpan.org/release/RRWO/Net-CIDR-Set-0.21/changes Release Notes
https://nvd.nist.gov/vuln/detail/CVE-2025-40911 Third Party Advisory US Government Resource
https://nvd.nist.gov/vuln/detail/CVE-2026-45191 Third Party Advisory US Government Resource
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