{"api_version":"1","generated_at":"2026-10-29T06:14:58+00:00","cve":"CVE-2026-116266","urls":{"html":"https://cve.report/CVE-2026-116266","api":"https://cve.report/api/cve/CVE-2026-116266.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-116266","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-116266"},"summary":{"title":"MIME::Head versions from 5.518 before 5.521 for Perl decode a partly encoded multipart boundary without flagging the parse as ambiguous","description":"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.","state":"PUBLISHED","assigner":"CPANSec","published_at":"2026-10-28 18:17:13","updated_at":"2026-10-28 18:17:13"},"problem_types":["CWE-436","CWE-436 CWE-436 Interpretation Conflict"],"metrics":[],"references":[{"url":"https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes","name":"https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes","refsource":"9b29abf9-4ab0-4765-b253-1875cd9b441e","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-116266","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116266","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[{"source":"CNA","title":"","value":"Upgrade to MIME-tools 5.521 or later.","time":"","lang":"en"}],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"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":{"dateUpdated":"2026-10-28T17:32:28.565Z","orgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","shortName":"CPANSec"},"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"}}},"cveMetadata":{"assignerOrgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","assignerShortName":"CPANSec","cveId":"CVE-2026-116266","datePublished":"2026-10-28T17:32:28.565Z","dateReserved":"2026-10-25T18:05:02.235Z","dateUpdated":"2026-10-28T17:32:28.565Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-28 18:17:13","lastModifiedDate":"2026-10-28 18:17:13","problem_types":["CWE-436","CWE-436 CWE-436 Interpretation Conflict"],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"116266","Ordinal":"1","Title":"MIME::Head versions from 5.518 before 5.521 for Perl decode a pa","CVE":"CVE-2026-116266","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"116266","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"MIME::Head versions from 5.518 before 5.521 for Perl decode a pa"}]}}}