CVE-2025-6216

Deeper analysis

Allegra contains an authentication bypass vulnerability in its password recovery mechanism, specifically within the calculateTokenExpDate function used to generate reset tokens. The flaw stems from reliance on a predictable value rather than a secure random one, enabling attackers to forge valid tokens. It affects multiple versions of the Allegra application prior to the fixes noted in the vendor's release documentation.

Remote, unauthenticated attackers can exploit the issue over the network to bypass authentication entirely and gain unauthorized access to affected installations. Successful exploitation allows full compromise of user accounts through the password reset process, with no user interaction or credentials required. The vulnerability received a CVSS v3 score of 9.8 and is tracked as ZDI-CAN-27104.

Vendor advisories recommend upgrading to Allegra release 8.1.4 or 7.5.2, as detailed in the official release notes. The corresponding Zero Day Initiative advisory ZDI-25-410 provides additional technical context on the flaw.

The EPSS score rose from lower values to a peak of 0.5306 on 2026-04-29 before receding to the current 0.4984, indicating emerging exploitation interest after disclosure.