CPANSA-MIME-tools-2026-116272: MIME-tools vulnerability

Publisher giterlizzi Document category csaf_security_advisory
Initial release date 2026-10-28T00:00:00 Engine CSAF Perl Toolkit 0.26
Current release date 2026-10-28T00:00:00 Build Date
Current version 1 Status final
CVSS v3.1 Base Score Severity
Original language Language en
Also referred to

Vulnerability Description

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.

Vulnerabilities

CVE-2026-116272

Vulnerability Description

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.

Weakness CWE-436 : Interpretation Conflict

Product status

Known affected
Product Score
MIME-tools less than 5.521
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity
Fixed

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

Revision history

Version Date of the revision Summary of the revision
1 Wed Oct 28 00:00:00 2026 First release

Sharing rules

TLP:WHITE
For the TLP version see: https://www.first.org/tlp/