Amavis before 2.12.3 and 2.13.x before 2.13.1, in part because of its use of MIME-tools, has an Interpretation Conflict (relative to some mail user agents) when there are multiple boundary parameters in a MIME email message. Consequently, there can be an incorrect check for banned files or malware.
https://www.amavis.org/release-notes.txt
https://metacpan.org/pod/MIME::Tools
https://lists.amavis.org/pipermail/amavis-users/2024-March/006811.html
https://gitlab.com/amavis/amavis/-/raw/v2.13.1/README_FILES/README.CVE-2024-28054