Session hijacking via unrotated login identifier
Published Sep 9, 2026 · Updated Sep 9, 2026
Session fixation in Tirreno before 0.10.0 allows attackers to access a victim's authenticated session through a fixed session identifier. The login authentication flow validates credentials and establishes the authenticated session without calling session_regenerate_id(), so the pre-login identifier remains valid. Exploitation requires planting a known identifier in the victim's browser through a man-in-the-middle position, cross-site scripting, or subdomain cookie injection; reuse grants the victim's session permissions.
Summary
What happened
Session fixation in Tirreno before 0.10.0 allows attackers to access a victim's authenticated session through a fixed session identifier. The login authentication flow validates credentials and establishes the authenticated session without calling session_regenerate_id(), so the pre-login identifier remains valid. Exploitation requires planting a known identifier in the victim's browser through a man-in-the-middle position, cross-site scripting, or subdomain cookie injection; reuse grants the victim's session permissions.
The record
- CVE
- CVE-2026-64857
- Published
- Sep 9, 2026
- Updated
- Sep 9, 2026
- Vendor
- Tirreno Technologies Sàrl
- Product
- Tirreno
- Classifications
- CWE-384, T1550.004
- Attack vector
- network
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 9, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.10.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo