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CVE-2026-19566

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

7.5 HighFix available

Net::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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
None
Availability
High

Exploit likelihood

0.63%Up 0.5 points since Aug 12, 2026
90%50%10%1%

What each source reports

CVE List Score used 7.5

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

Net::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.

Record
CVE-2026-19566
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-1284, CWE-789
Updated
2026-11-02
EUVDEUVD-2026-57150 7.5

Net::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.

Record
EUVD-2026-57150
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
NVD 7.5

Net::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.

Record
CVE-2026-19566
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-789, CWE-1284
Updated
2026-11-02
OSV 7.5

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

Net::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.

Record
CVE-2026-19566
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-1284, CWE-789
Updated
2026-11-02
OSVDEBIAN-CVE-2026-19566 7.5

Net::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.

Record
DEBIAN-CVE-2026-19566
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVUBUNTU-CVE-2026-19566 7.5

Net::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.

Record
UBUNTU-CVE-2026-19566
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVopenSUSE-SU-2026:11550-1 No score

perl-Net-CIDR-Set-0.230.0-1.1 on GA media

These are all security issues fixed in the perl-Net-CIDR-Set-0.230.0-1.1 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2026:11550-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
libnet-cidr-set-perl
Debian:12
All versions, plus listed versions
0.13-40.13-50.15-10.19-10.20-10.21-10.22-10.23-1
None known
libnet-cidr-set-perl
Debian:13
All versions, plus listed versions
0.15-10.15-1+deb13u10.19-10.20-10.21-10.22-10.23-1
None known
libnet-cidr-set-perl
Debian:14
before 0.23-1, plus listed versions
0.15-10.19-10.20-10.21-10.22-1
0.23-1
libnet-cidr-set-perl
Ubuntu:20.04:LTS
All versions, plus listed versions
0.13-2
None known
libnet-cidr-set-perl
Ubuntu:22.04:LTS
All versions, plus listed versions
0.13-3
None known
libnet-cidr-set-perl
Ubuntu:24.04:LTS
All versions, plus listed versions
0.13-40.13-5
None known
libnet-cidr-set-perl
Ubuntu:26.10
All versions, plus listed versions
0.19-10.20-10.21-10.22-10.23-1
None known
libnet-cidr-set-perl
Ubuntu:26.04:LTS
All versions, plus listed versions
0.19-1
None known
perl-Net-CIDR-Set
openSUSE:Tumbleweed
before 0.230.0-1.1
0.230.0-1.1

History

History
RecordedChangedSources
first indexedCVE List, EUVD, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-19566 is a high vulnerability (CVSS 7.5) in Rrwo Net::cidr::set, published August 12, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.63%, the 50th percentile. Fixed in libnet-cidr-set-perl 0.23-1.

References

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