CVE-2026-64857 tirreno has Session Fixation in Login Authentication
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-64857?
CVE-2026-64857 is a medium-severity vulnerability in tirrenotechnologies tirreno, published on 9 Sep 2026.
Official description
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.
Weakness: CWE-384
Which versions are affected by CVE-2026-64857?
How do I fix CVE-2026-64857?
No fix has been published for CVE-2026-64857 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-64857 being exploited?
There is no known exploitation of CVE-2026-64857 in the wild and no public exploit code.
Sources
Also known as GHSA-gwcm-4p9m-9mvr.