{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-64194",
        "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "state": "PUBLISHED",
        "assignerShortName": "CPANSec",
        "dateReserved": "2026-07-19T10:13:00.756Z",
        "datePublished": "2026-07-20T17:55:05.169Z",
        "dateUpdated": "2026-08-30T20:06:49.756Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "collectionURL": "https://cpan.org/modules",
                    "defaultStatus": "unaffected",
                    "packageName": "Net-DNS",
                    "product": "Net::DNS",
                    "programFiles": [
                        "lib/Net/DNS/DomainName.pm"
                    ],
                    "programRoutines": [
                        {
                            "name": "Net::DNS::DomainName::decode"
                        }
                    ],
                    "repo": "https://www.net-dns.org/svn/net-dns/",
                    "vendor": "NLNETLABS",
                    "versions": [
                        {
                            "lessThanOrEqual": "1.55",
                            "status": "affected",
                            "version": "0",
                            "versionType": "custom"
                        }
                    ]
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "reporter",
                    "value": "Steffen Ullrich"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Net::DNS versions through 1.55 for Perl allow Denial of Service via deep DNS compression pointer chains.\n\nNet::DNS::DomainName::decode follows RFC 1035 compression pointers by recursing into itself with no depth limit. It is possible to construct a name which saturates the call stack (at least with larger TCP responses), leading to a potential Denial of Service.\n\nThe guard `$link < $offset` prevents forward and circular chains, but still allows arbitrarily long backward chains. The per-offset cache (`$cache`) is populated at the start of each call and short-circuits only re-traverses of the same offset - the initial descent through a fresh chain still recurses at full depth.\n\nA crafted packet can chain two-byte compression pointers so that each one points two bytes earlier than the previous, producing a chain length of `offset / 2`. For the 14-bit pointer field (max offset 16383) this gives up to ~8191 recursive frames. For a TCP DNS message the limit is the 16-bit length field (~32767 frames). Perl's default C stack handles only a few thousand frames; beyond that the process receives SIGSEGV or similar, which is a denial-of-service for any application parsing untrusted DNS data.\n\nThe vulnerability is triggered by `Net::DNS::Packet->new(\\$wire)` i.e. any point where the library decodes a DNS message from the network."
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-674",
                            "description": "CWE-674 Uncontrolled Recursion",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
                "shortName": "CPANSec",
                "dateUpdated": "2026-07-20T17:55:05.169Z"
            },
            "references": [
                {
                    "url": "https://www.net-dns.org/blog/#release-candidate-for-netdns-1.56"
                },
                {
                    "tags": [
                        "issue-tracking"
                    ],
                    "url": "https://rt.cpan.org/Ticket/Display.html?id=179946"
                },
                {
                    "tags": [
                        "release-notes"
                    ],
                    "url": "https://metacpan.org/release/NLNETLABS/Net-DNS-1.55_01/changes"
                }
            ],
            "solutions": [
                {
                    "lang": "en",
                    "value": "Upgrade to version 1.56 or later."
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "timeline": [
                {
                    "lang": "en",
                    "time": "2026-07-10T00:00:00.000Z",
                    "value": "Issue reported publicly via RT."
                },
                {
                    "lang": "en",
                    "time": "2026-07-10T00:00:00.000Z",
                    "value": "Version 1.55_01 (release candidate for version 1.56) published on CPAN."
                },
                {
                    "lang": "en",
                    "time": "2026-07-18T00:00:00.000Z",
                    "value": "Version 1.56 published on CPAN."
                }
            ],
            "title": "Net::DNS versions through 1.55 for Perl allow Denial of Service via deep DNS compression pointer chains",
            "x_generator": {
                "engine": "cpansec-cna-tool 0.1"
            }
        },
        "adp": [
            {
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "http://www.openwall.com/lists/oss-security/2026/07/20/13"
                    },
                    {
                        "url": "https://lists.debian.org/debian-lts-announce/2026/08/msg00052.html"
                    }
                ],
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2026-08-30T20:06:49.756Z"
                }
            },
            {
                "metrics": [
                    {
                        "cvssV3_1": {
                            "scope": "UNCHANGED",
                            "version": "3.1",
                            "baseScore": 7.5,
                            "attackVector": "NETWORK",
                            "baseSeverity": "HIGH",
                            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                            "integrityImpact": "NONE",
                            "userInteraction": "NONE",
                            "attackComplexity": "LOW",
                            "availabilityImpact": "HIGH",
                            "privilegesRequired": "NONE",
                            "confidentialityImpact": "NONE"
                        }
                    },
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-07-21T18:55:36.580996Z",
                                "id": "CVE-2026-64194",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-07-21T18:56:01.149Z"
                }
            }
        ]
    }
}