Bug 2563417

Summary: CVE-2026-116272 perl-MIME-tools: perl-mime-tools: Security filter bypass via nested comments in boundary parameters [fedora-rawhide]
Product: [Fedora] Fedora Reporter: Marian Rehak <mrehak>
Component: perl-MIME-toolsAssignee: Paul Howarth <paul>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: paul, perl-devel
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["73a6ff40-77b3-4983-b32e-0a7179b9f82f"]}
Fixed In Version: perl-MIME-tools-5.522-1.fc45 perl-MIME-tools-5.522-1.fc44 perl-MIME-tools-5.522-1.fc43 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-11-06 01:15:29 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2563048    

Description Marian Rehak 2026-10-29 15:15:22 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Fedora Update System 2026-10-30 08:33:08 UTC
FEDORA-2026-51fdfb7476 (perl-MIME-tools-5.522-1.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-51fdfb7476

Comment 2 Fedora Update System 2026-10-30 08:34:26 UTC
FEDORA-2026-0e79d6ad13 (perl-MIME-tools-5.522-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-0e79d6ad13

Comment 3 Fedora Update System 2026-10-30 08:35:31 UTC
FEDORA-2026-a415b3bf48 (perl-MIME-tools-5.522-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-a415b3bf48

Comment 4 Fedora Update System 2026-11-06 01:15:29 UTC
FEDORA-2026-51fdfb7476 (perl-MIME-tools-5.522-1.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 5 Fedora Update System 2026-11-06 01:25:28 UTC
FEDORA-2026-0e79d6ad13 (perl-MIME-tools-5.522-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 6 Fedora Update System 2026-11-06 01:50:19 UTC
FEDORA-2026-a415b3bf48 (perl-MIME-tools-5.522-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.