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

CVE ID : CVE-2026-23901 Published : Feb. 10, 2026, 10:15 a.m. | 32 minutes ago Description : 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   discusses this as well. Typically, brute force attack can be mitigated at the infrastructure level. Severity: 1.0 | LOW Visit the link for more details, such as CVSS details, affected products, timeline, and more...