CVE-2026-64857

19th percentile - higher than 19% of all known CVEs

tirreno, a security framework, has a session fixation issue in versions prior to 0.10.0. During authentication, tirreno validates the user's credentials and establishes the authenticated session, but it does not call `session_regenerate_id()` afterward. As a result, the session identifier is not rotated on login, it stays the same before and after authentication. An attacker able to fix a known session identifier in a victim's browser (for example through a network man-in-the-middle position, or a separate cross-site scripting or subdomain cookie-injection issue) could then gain access to the victim's authenticated session. The issue is fixed in v0.10.0. The session identifier is now regenerated on successful authentication, and the previous session is destroyed. There is no configuration-level workaround.

The risk involves the potential for an attacker to hijack an authenticated user's session, which could lead to unauthorized access to accounts and data.

Immediately update tirreno to version 0.10.0 or later, as there is no configuration workaround.