CVE-2026-56091

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://vulners.com/cve/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 Shiro

CVSS 4.0

8.2 HIGH

EPSS

0.4% (36th percentile)

Weakness

CWE-289

NVD status

Deferred

Published

2026-06-25