Vulnerability · Published Feb 9, 2026 · Assigned by apache
CVE-2026-23903Apache Shiro: Auth bypass when accessing static files only on case-insensitive filesystems
Medium 5.3
In plain English
A medium-severity security flaw in Apache Shiro from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | shiro | no fix listed | DEBIAN-CVE-2026-23903 |
| Debian:13 | shiro | no fix listed | DEBIAN-CVE-2026-23903 |
| Debian:14 | shiro | no fix listed | DEBIAN-CVE-2026-23903 |
| Maven | org.apache.shiro:shiro-spring | 2.1.0 | GHSA-c244-p6m5-vqj6 |
| Ubuntu:22.04:LTS | shiro | no fix listed | UBUNTU-CVE-2026-23903 |
| Ubuntu:25.10 | shiro | no fix listed | UBUNTU-CVE-2026-23903 |
| Ubuntu:26.04:LTS | shiro | no fix listed | UBUNTU-CVE-2026-23903 |
| Ubuntu:26.10 | shiro | no fix listed | UBUNTU-CVE-2026-23903 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache Shiro | 0 – before 2.0.7 |
Weakness: CWE-289 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N