GNU Mailman 2.x before 2.1.30 uses the .obj extension for scrubbed application/octet-stream MIME parts. This behavior may contribute to XSS attacks against list-archive visitors, because an HTTP reply from an archive web server may lack a MIME type, and a web browser may perform MIME sniffing, conclude that the MIME type should have been text/html, and execute JavaScript code.
Cross-site scripting vulnerability in Mailman 2.1.26 and earlier allows remote authenticated attackers to inject arbitrary web script or HTML via unspecified vectors.
Pipermail in Mailman stores private mail messages with predictable filenames in a world-executable directory, which allows local users to read private mailing list archives.
Cross-site scripting vulnerability in Mailman email archiver before 2.08 allows attackers to obtain sensitive information or authentication credentials via a malicious link that is accessed by other web users.