{"id":"CVE-2026-116266","published":"2026-10-28T18:17:13.017","lastModified":"2026-10-28T18:17:13.017","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-436"],"vendors":[],"products":[],"references":[{"url":"https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}