Session Fixation in Apache Shiro - CVE-2026-43827
Published: August 25, 2026
Vulnerability identifier: #VU145290
CSH Severity: Medium
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-43827
CWE-ID: CWE-384
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to fixate a session and hijack a user's authenticated session.
The vulnerability exists due to improper session management in the authentication session handling logic when processing a successful login for an existing session. A remote user can supply or reuse a known session identifier before login to fixate a session and hijack a user's authenticated session.
The issue occurs because an existing session is not invalidated and a new session identifier is not generated after successful login.
Affected software
Apache Shiro
How to mitigate CVE-2026-43827
Install security update from vendor's website.
Apache Shiro - update to 2.1.1