CVE-2026-23901Apache Shiro: Brute force attack possible to determine valid user names

Beschreibung

Observable Timing Discrepancy vulnerability in Apache Shiro. This issue affects Apache Shiro: from 1.*, 2.* before 2.0.7. Users are recommended to upgrade to version 2.0.7 or later, which fixes the issue. Prior to Shiro 2.0.7, code paths for non-existent vs. existing users are different enough, that a brute-force attack may be able to tell, by timing the requests only, determine if the request failed because of a non-existent user vs. wrong password. The most likely attack vector is a local attack only. Shiro security model  https://shiro.apache.org/security-model.html#username_enumeration  discusses this as well. Typically, brute force attack can be mitigated at the infrastructure level.

Daten: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Wiedergegeben wie in der Quelle, auf Englisch.

Betroffene Produkte und Versionen

Referenzen und Patches

• https://lists.apache.org/thread/mm1jct9b86jvnh3y44tj22xvjtx3xhhh vendor-advisoryIssue TrackingMailing ListThird Party Advisory
• http://www.openwall.com/lists/oss-security/2026/02/08/2 Mailing ListThird Party Advisory