CVE-2026-19566
Received
Received - Intake
Memory Exhaustion in Net::CIDR::Set Perl Module
Vulnerability report for CVE-2026-19566, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-12
Last updated on: 2026-08-12
Assigner: CPANSec
Description
Description
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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| 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. |
| CWE-1284 | The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties. |
