CVE-2026-116272
MIME::Field::ParamVal versions before 5.521 for Perl do not flag a duplicate boundary parameter whose name contains a nested comment.
Impact
MIME::Field::ParamVal versions before 5.521 for Perl do not flag a duplicate boundary parameter whose name contains a nested comment. A parameter written boundary((c))="A" or boundary(\))="A" is stored under that literal name rather than as boundary. A second boundary parameter is then not reported as a duplicate, and MIME::Parser splits the message on it. Readers that skip comments as RFC 5322 allows take the first boundary instead. A remote sender can hide an attachment from a filter that relies on ambiguous_content() while the recipient's mail client shows it.
Affected products
| Product | Affected versions |
|---|---|
| MIME::Field::ParamVal | before 5.521 |
Versions were read from the advisory text. No structured product data has been published for this record yet.