CVE-2026-23903: Apache Shiro

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Authentication Bypass by Alternate Name vulnerability in Apache Shiro. This issue affects Apache Shiro: before 2.0.7. Users are recommended to upgrade to version 2.0.7, which fixes the issue. The issue only effects static files. If static files are served from a case-insensitive filesystem, such as default macOS setup, static files may be accessed by varying the case of the filename in the request. If only lower-case (common default) filters are present in Shiro, they may be bypassed this way. Shiro 2.1.0 and later has a new parameters to remediate this issue shiro.ini: filterChainResolver.caseInsensitive = true application.properties: shiro.caseInsensitive=true Shiro 3.0.0 and later makes this the default in shiro.ini-based configurations. Shiro 3.0.1 and later makes this the default in all configurations, including programmatic and Spring / Spring Boot.

Affected products

• Apache Shiro: before 2.0.7 (fixed in 2.0.7)

Published 2026-02-09. Last modified 2026-08-20.