{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-116266",
        "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "state": "PUBLISHED",
        "assignerShortName": "CPANSec",
        "dateReserved": "2026-10-25T18:05:02.235Z",
        "datePublished": "2026-10-28T17:32:28.565Z",
        "dateUpdated": "2026-10-28T17:32:28.565Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "collectionURL": "https://cpan.org/modules",
                    "defaultStatus": "unaffected",
                    "modules": [
                        "MIME::Head"
                    ],
                    "packageName": "MIME-tools",
                    "packageURL": "pkg:cpan/MIME-tools",
                    "programFiles": [
                        "lib/MIME/Head.pm",
                        "lib/MIME/Field/ParamVal.pm"
                    ],
                    "programRoutines": [
                        {
                            "name": "MIME::Head::multipart_boundary"
                        },
                        {
                            "name": "MIME::Field::ParamVal::parse_params"
                        }
                    ],
                    "repo": "https://salsa.debian.org/dskoll/mime-tools",
                    "versions": [
                        {
                            "lessThan": "5.521",
                            "status": "affected",
                            "version": "5.518",
                            "versionType": "custom"
                        }
                    ]
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "MIME::Head versions from 5.518 before 5.521 for Perl decode a partly encoded multipart boundary without flagging the parse as ambiguous.\n\nThe multipart_boundary() method decodes RFC 2047 encoded words anywhere in the boundary, but the ambiguity check only fires when the whole value is one encoded word. A boundary such as abc=?us-ascii?Q?def?= is used as abcdef, and ambiguous_content() returns false.\n\nEncoded words are not allowed in parameters, so other mail readers split the message on the literal value. A remote sender can hide an attachment from a filter that relies on ambiguous_content() while the recipient's mail client shows it."
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-436",
                            "description": "CWE-436 Interpretation Conflict",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
                "shortName": "CPANSec",
                "dateUpdated": "2026-10-28T17:32:28.565Z"
            },
            "references": [
                {
                    "tags": [
                        "release-notes"
                    ],
                    "url": "https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes"
                }
            ],
            "solutions": [
                {
                    "lang": "en",
                    "value": "Upgrade to MIME-tools 5.521 or later."
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "title": "MIME::Head versions from 5.518 before 5.521 for Perl decode a partly encoded multipart boundary without flagging the parse as ambiguous",
            "x_generator": {
                "engine": "cpansec-cna-tool 0.1"
            }
        }
    }
}