{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-63435",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-07-16T19:35:57.767Z",
        "datePublished": "2026-09-01T20:09:20.820Z",
        "dateUpdated": "2026-09-01T20:09:20.820Z"
    },
    "containers": {
        "cna": {
            "title": "Mail: Email address spoofing via malformed RFC 2047 encoded-words",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-436",
                            "lang": "en",
                            "description": "CWE-436: Interpretation Conflict",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 5.3,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "LOW",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/mikel/mail/security/advisories/GHSA-mvxr-6m87-mv2q",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/mikel/mail/security/advisories/GHSA-mvxr-6m87-mv2q"
                },
                {
                    "name": "https://github.com/mikel/mail/pull/1664",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mikel/mail/pull/1664"
                },
                {
                    "name": "https://github.com/mikel/mail/commit/f9d59c2e447af42e2c3dec5a56b1bb25c7292859",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mikel/mail/commit/f9d59c2e447af42e2c3dec5a56b1bb25c7292859"
                },
                {
                    "name": "https://github.com/mikel/mail/releases/tag/2.9.1",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/mikel/mail/releases/tag/2.9.1"
                }
            ],
            "affected": [
                {
                    "vendor": "mikel",
                    "product": "mail",
                    "versions": [
                        {
                            "version": "< 2.9.1",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-09-01T20:09:20.820Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Mail is an internet library for Ruby designed to handle email generation, parsing, and sending. Prior to 2.9.1, Mail::Utilities.q_value_decode and Mail::Utilities.b_value_decode used a single String#match and an overly greedy charset capture to decode only the first RFC 2047 encoded-word and mishandle surrounding or subsequent text. A crafted malformed encoded-word in an address display name or local part could cross ? delimiters and make decoded From, To, or Reply-To header values differ from the raw values inspected by a human reviewer or downstream parser, enabling apparent sender or recipient spoofing, phishing, or authorization-check bypass. This issue is fixed in version 2.9.1."
                }
            ],
            "source": {
                "advisory": "GHSA-mvxr-6m87-mv2q",
                "discovery": "UNKNOWN"
            }
        }
    }
}