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.

Project Subscriptions

Vendors Products
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-c4qc-4q9p-m9q9 Apache Shiro Affected by an Observable Timing Discrepancy Vulnerability
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

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'}


Projects

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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 : Awaiting Analysis

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

Modified: 2026-02-10T15:22:54.740

Link: CVE-2026-23901

cve-icon Redhat

Severity : Low

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

Links: CVE-2026-23901 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-02-10T15:37:14Z

Weaknesses