{"id":"CVE-2026-19566","summary":"Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths","details":"Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths.\n\nThe _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.\n\nAny 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.","aliases":["GHSA-grjr-r4x5-mx4p"],"modified":"2026-08-15T04:25:18.858666667Z","published":"2026-08-12T08:39:59.029Z","database_specific":{"cwe_ids":["CWE-1284","CWE-789"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19566.json","cna_assigner":"CPANSec"},"references":[{"type":"WEB","url":"https://cpan.org/modules"},{"type":"WEB","url":"https://www.cve.org/CVERecord?id=CVE-2026-49942"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/19xxx/CVE-2026-19566.json"},{"type":"ADVISORY","url":"https://github.com/robrwo/perl-Net-CIDR-Set/security/advisories/GHSA-grjr-r4x5-mx4p"},{"type":"ADVISORY","url":"https://metacpan.org/release/RRWO/Net-CIDR-Set-0.23/changes"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19566"},{"type":"FIX","url":"https://github.com/robrwo/perl-Net-CIDR-Set/commit/e16b27db676fd1ca671fbb31208a22c1b1ba9724.patch"},{"type":"PACKAGE","url":"https://github.com/robrwo/perl-Net-CIDR-Set"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/robrwo/perl-net-cidr-set","events":[{"introduced":"0"},{"fixed":"a56d59cdfbe14cb3ae051acbd1ea12f6734ff130"},{"fixed":"e16b27db676fd1ca671fbb31208a22c1b1ba9724"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.23"}],"source":["DESCRIPTION","REFERENCES"]}}],"versions":["0.21","0.20","0.19","0.18","0.17","0.16","v0.15","v0.14","v0.13"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-19566.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}