SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-23903

Authentication Bypass by Alternate Name vulnerability in Apache Shiro.

MEDIUM 5.3EPSS 0.40%

Does this matter?

Lower severity and a low EPSS score (0.40%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS
0.40% probability · 34th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-289
Affected
apache/shiro
Source
security@apache.org
EPSS trend
0%3%5%26 October 2026: 0.40%26 October 202626 October 2026

EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.