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.
History

Thu, 12 Feb 2026 15:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:apache:shiro:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 2.9, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'}

cvssV3_1

{'score': 2.5, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N'}


Wed, 11 Feb 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 2.9, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'}

threat_severity

Low


Tue, 10 Feb 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 10 Feb 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Apache
Apache shiro
Vendors & Products Apache
Apache shiro

Tue, 10 Feb 2026 11:30:00 +0000

Type Values Removed Values Added
References

Tue, 10 Feb 2026 09:45:00 +0000

Type Values Removed Values Added
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  https://shiro.apache.org/security-model.html#username_enumeration  discusses this as well. Typically, brute force attack can be mitigated at the infrastructure level.
Title Apache Shiro: Brute force attack possible to determine valid user names
Weaknesses CWE-208
References
Metrics cvssV4_0

{'score': 1, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:A/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/S:N/AU:Y/R:A/V:C/RE:L/U:Green'}


cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2026-02-10T15:31:25.166Z

Reserved: 2026-01-17T18:01:53.140Z

Link: CVE-2026-23901

cve-icon Vulnrichment

Updated: 2026-02-10T10:22:44.721Z

cve-icon NVD

Status : Analyzed

Published: 2026-02-10T10:15:59.240

Modified: 2026-02-12T15:30:25.543

Link: CVE-2026-23901

cve-icon Redhat

Severity : Low

Publid Date: 2026-02-10T09:25:51Z

Links: CVE-2026-23901 - Bugzilla