Vulnerability Database

324,311

Total vulnerabilities in the database

CVE-2026-23901

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.

  • Published: Feb 10, 2026
  • Updated: Feb 13, 2026
  • CVE: CVE-2026-23901
  • Severity: Low
  • Exploit:

CVSS v3:

  • Severity: Low
  • Score: 2.5
  • AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N

CWEs: