{"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":"2026-11-05T20:21:17.253Z"},"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"}},"adp":[{"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.3,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","integrityImpact":"LOW","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-11-05T20:21:08.416154Z","id":"CVE-2026-116266","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":"2026-11-05T20:21:17.253Z"}}]}}