CVE-2026-43827 PUBLISHED

Apache Shiro: Session fixation: new session is not created after login by default

Assigner: apache
Reserved: 02.05.2026 Published: 25.05.2026 Updated: 26.05.2026

Default configurations of Apache Shiro have a session fixation vulnerability.

This issue affects Apache Shiro from 1.0 to 2.1.0, and 3.0.0-alpha-1.

Users are recommended to upgrade to version 2.1.1, or 3.0.0-alpha-2 or later, which fixes the issue.

In the affected versions, when a session already exists, it is not invalidated upon successful login, nor is a new session being generated with a new ID.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N/AU:Y/R:U/RE:L/U:Amber
CVSS Score: 5.9

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	Low
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	Active

CVSS 4.0

Product Status

Vendor	Apache Software Foundation
Product	Apache Shiro
Versions	Default: unaffected affected from 1.0 to 2.1.0 (incl.) affected from 3.0.0-alpha-0 to 3.0.0-alpha-1 (incl.)

Credits

Rasmus Moorats <xx@nns.ee> finder
Lenny Primak <lenny@flowlogix.com> remediation developer

References

https://shiro.apache.org/security-reports.html#cve_2026_43827

Problem Types

CWE-384 Session Fixation CWE