CVE-2026-56091: Apache Software Foundation Apache Shiro

High severity, CVSS 8.2. EPSS: 0.7% chance of exploitation in the next 30 days.

When using Apache Shiro with the shiro-guice module in a web servlet context, a specially crafted HTTP request may cause an authentication bypass. This vulnerability is similar to https://www.cve.org/CVERecord?id=CVE-2020-1957 https://www.cve.org/CVERecord , except that it affects the `shiro-guice` module instead of the `shiro-spring` module. This issue affects all Apache Shiro versions through 2.x, and 3.0.0-alpha-1 only when using `shiro-guice` module in a web servlet context. Upgrade to version 3.0.0 or later, which fixes the issue.

Affected products

• Apache Software Foundation Apache Shiro: up to and including 2.99.99; from 3.0.0-alpha-0, up to and including 3.0.0-alpha-1

Published 2026-06-25. Last modified 2026-06-25.