RRWO Net::CIDR::Set up to 0.22 _encode memory allocation

Summaryinfo

A vulnerability was found in RRWO Net::CIDR::Set up to 0.22. It has been rated as problematic. This impacts the function _encode. This manipulation causes memory allocation. The identification of this vulnerability is CVE-2026-19566. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in RRWO Net::CIDR::Set up to 0.22. It has been declared as problematic. Affected by this vulnerability is the function _encode. The manipulation with an unknown input leads to a memory allocation vulnerability. The CWE definition for the vulnerability is CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-19566 since 08/11/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available.

Upgrading to version 0.23 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• RRWO

Name

• Net::CIDR::Set

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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