Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-19566
StatePUBLISHED
AssignerCPANSec
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-12 09:17:29 UTC
Updated2026-08-12 09:17:29 UTC
DescriptionNet::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths. The _encode method accepts any prefix length matching `(0|[1-9][0-9]*)` and passes it to _width2bits(), which builds the mask as `'1' x ($width + 8)`, one character per bit. The _inc() method then unpacks the packed mask into a Perl array of one scalar per byte, so the prefix length alone sets the allocation size: `::/100000000` builds a 100 MB string and a 12.5 million element array. The value being tested is parsed, not just the configured ranges: contains() builds a set from its argument, and _guess_coder() tries the IPv4 coder and then the IPv6 coder, so an IPv4-only set expands an oversized IPv6 prefix length before the mixed address width check rejects it. Any caller that passes untrusted input to contains() or add() can exhaust process memory. A prefix length above 128 is also stored as a range that does not match the requested block: 2001:db8::/129 stringifies back unchanged, contains() of its own base address returns false, and removing it from a set drops the base address while the set still prints as covering it.

Risk And Classification

Problem Types: CWE-789 | CWE-1284 | CWE-1284 CWE-1284 Improper Validation of Specified Quantity in Input | CWE-789 CWE-789 Memory Allocation with Excessive Size Value

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA RRWO NetCIDRSet affected 0.23 custom Not specified

References

ReferenceSourceLinkTags
github.com/robrwo/perl-Net-CIDR-Set/security/advisories/GHSA-grjr-r4x5-mx4p 9b29abf9-4ab0-4765-b253-1875cd9b441e github.com
metacpan.org/release/RRWO/Net-CIDR-Set-0.23/changes 9b29abf9-4ab0-4765-b253-1875cd9b441e metacpan.org
github.com/robrwo/perl-Net-CIDR-Set/commit/e16b27db676fd1ca671fbb31208a2... 9b29abf9-4ab0-4765-b253-1875cd9b441e github.com
www.cve.org/CVERecord 9b29abf9-4ab0-4765-b253-1875cd9b441e www.cve.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Solutions

CNA: Upgrade to Net::CIDR::Set version 0.23 or later.

Workarounds

CNA: For deployments that cannot upgrade, apply the patch.

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