Apache Shiro up to 2.1.0/3.0.0-alpha-1 session fixiation

Summaryinfo

A vulnerability marked as critical has been reported in Apache Shiro up to 2.1.0/3.0.0-alpha-1. This affects an unknown part. Performing a manipulation results in session fixiation. This vulnerability is known as CVE-2026-43827. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Apache Shiro up to 2.1.0/3.0.0-alpha-1. This affects an unknown code. The manipulation with an unknown input leads to a session fixiation vulnerability. CWE is classifying the issue as CWE-384. Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at shiro.apache.org. This vulnerability is uniquely identified as CVE-2026-43827 since 05/03/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/01/2026).

The vulnerability scanner Nessus provides a plugin with the ID 316789 (Linux Distros Unpatched Vulnerability : CVE-2026-43827), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.1.1 or 3.0.0-alpha-2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (316789). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• Apache

Name

• Shiro

Version

• 2.0
• 2.1.0
• 3.0.0-alpha-1

License

• open-source

Website

• Vendor: https://www.apache.org/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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