{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-103602",
        "assignerOrgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
        "state": "PUBLISHED",
        "assignerShortName": "bcorg",
        "dateReserved": "2026-09-30T23:01:10.053Z",
        "datePublished": "2026-10-02T07:10:03.885Z",
        "dateUpdated": "2026-10-02T17:49:42.601Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
                "shortName": "bcorg",
                "dateUpdated": "2026-10-02T07:10:03.885Z"
            },
            "title": "Name constraints bypass via trailing dot in rfc822Name, dNSName and URI hosts",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "cweId": "CWE-295",
                            "description": "CWE-295 Improper Certificate Validation",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "impacts": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "Integrity (bypass of excluded rfc822Name, dNSName and uniformResourceIdentifier name constraints during certification path validation: certificates naming hosts inside an excluded subtree are accepted)"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "Legion of the Bouncy Castle Inc.",
                    "product": "bc-csharp",
                    "collectionURL": "https://www.nuget.org/packages/BouncyCastle.Cryptography",
                    "packageName": "BouncyCastle.Cryptography",
                    "repo": "https://github.com/bcgit/bc-csharp",
                    "programFiles": [
                        "crypto/src/pkix/PkixNameConstraintValidator.cs",
                        "crypto/src/pkix/NameConstraintUtilities.cs",
                        "crypto/src/pkix/NameConstraintEmail.cs",
                        "crypto/src/pkix/NameConstraintDns.cs",
                        "crypto/src/pkix/NameConstraintUri.cs"
                    ],
                    "versions": [
                        {
                            "status": "affected",
                            "version": "0",
                            "lessThan": "2.7.0",
                            "versionType": "semver"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Improper certificate validation in PkixNameConstraintValidator in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who controls, or can obtain certificates from, a name-constrained intermediate CA to have certificates accepted during PKIX certification path validation for email addresses, DNS names or URI hosts that lie within excluded subtrees applying to that CA, via an rfc822Name, dNSName or uniformResourceIdentifier name whose host ends with a dot, because names and constraints were compared without first removing the RFC 1034 root-label trailing dot, so a fully qualified host name did not match an excluded subtree for the same host written without the dot.",
                    "supportingMedia": [
                        {
                            "type": "text/html",
                            "base64": false,
                            "value": "Improper certificate validation in PkixNameConstraintValidator in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who controls, or can obtain certificates from, a name-constrained intermediate CA to have certificates accepted during PKIX certification path validation for email addresses, DNS names or URI hosts that lie within excluded subtrees applying to that CA, via an rfc822Name, dNSName or uniformResourceIdentifier name whose host ends with a dot, because names and constraints were compared without first removing the RFC 1034 root-label trailing dot, so a fully qualified host name did not match an excluded subtree for the same host written without the dot."
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://github.com/bcgit/bc-csharp/wiki/CVE-2026-103602",
                    "tags": [
                        "vendor-advisory"
                    ]
                },
                {
                    "url": "https://github.com/bcgit/bc-csharp/commit/f196a22bbf7765cc19b0c4f4645c74ea7ad35e09",
                    "tags": [
                        "patch"
                    ]
                },
                {
                    "url": "https://github.com/bcgit/bc-csharp/commit/be276e057775a6a674a62e9d9a2583b229978f73",
                    "tags": [
                        "patch"
                    ]
                },
                {
                    "url": "https://github.com/bcgit/bc-csharp/commit/75c3c576602886180ed92a63c89419e3bd63b392",
                    "tags": [
                        "patch"
                    ]
                }
            ],
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                {
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ],
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "HIGH",
                        "subIntegrityImpact": "NONE",
                        "vulnAvailabilityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "exploitMaturity": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "valueDensity": "NOT_DEFINED",
                        "vulnerabilityResponseEffort": "NOT_DEFINED",
                        "providerUrgency": "NOT_DEFINED",
                        "version": "4.0",
                        "baseSeverity": "HIGH",
                        "baseScore": 8.2,
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
                    }
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Discovered by Claude, Anthropic's AI assistant, and triaged by the Anthropic security team in collaboration with Anthropic Research.",
                    "type": "finder"
                }
            ],
            "source": {
                "discovery": "EXTERNAL"
            },
            "x_generator": {
                "engine": "Claude Opus 5.5"
            },
            "x_antReportIds": [
                "ANT-2026-DXGD77QP"
            ]
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-10-02T17:49:31.345892Z",
                                "id": "CVE-2026-103602",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
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                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
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                    "shortName": "CISA-ADP",
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}