ZDI-26-358: Allegra downloadAttachment Cross-Site Scripting Authentication Bypass Vulnerability

This vulnerability allows remote attackers to execute arbitrary script on affected installations of Allegra. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The ZDI has assigned a CVSS rating of 4.6. The following CVEs are assigned: CVE-2026-11443.