TI-2026-19257 Aliases CVE-2026-23901 GHSA-c4qc-4q9p-m9q9

Apache Shiro: Brute force attack possible to determine valid user names

LOW 6CWE-208Published 2026-02-10 · Updated 2026-02-10

Key facts

Attack vector: Local
Privileges required: Low
User interaction: Active
Attack complexity: High
Attack requirements: Present
Impact type: Information disclosure
Confidentiality · integrity · availability: Low · None · None
Fix status: Partial Red Hat: 5 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-208.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.0023 13th percentileScored 2026-11-07

Fix Partial Apache Shiro (Apache Software Foundation): 2.0.7org.apache.shiro:shiro-core (Maven): 2.1.0Red Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Apache	Apache Shiro	before 2.0.7	2.0.7	Patch available	CNA
—	org.apache.shiro:shiro-core (Maven)	before 2.1.0	2.1.0	Patch available	GHSA-c4qc-4q9p-m9q9

Apache Shiro VendorApache Affected before 2.0.7 Fixed in 2.0.7 Patch available CNA
org.apache.shiro:shiro-core (Maven) Vendor— Affected before 2.1.0 Fixed in 2.1.0 Patch available GHSA-c4qc-4q9p-m9q9

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:apache:shiro::::::::	before 2.0.7	Vulnerable	Apache

cpe:2.3:a:apache:shiro:*:*:*:*:*:*:*:* Versions before 2.0.7 Vulnerable ·Apache

Remediation

Fix · CNA Apache Shiro (Apache Software Foundation) Fixed in 2.0.7
Fix · GHSA-c4qc-4q9p-m9q9 org.apache.shiro:shiro-core (Maven) Fixed in 2.1.0 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Fuse 7	Affected	No fix yet: Fix deferred
Red Hat JBoss Enterprise Application Platform 7	Affected	No fix yet: Fix deferred
Red Hat JBoss Enterprise Application Platform 8	Affected	No fix yet: Fix deferred
Red Hat JBoss Enterprise Application Platform Expansion Pack	Affected	No fix yet: Fix deferred
Red Hat build of Apache Camel for Spring Boot 4	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-23901
2026-10-03 Alias added: GHSA-c4qc-4q9p-m9q9

References

Advisory 3

Other 1

https://github.com/apache/shiro

TI-2016-03813 Apache Shiro before 1.2.5, when a cipher key has not been configured for the "remember… KEVCVSS 3.1CRITICAL 9.8
TI-2020-13272 Improper authentication in Apache Shiro CVSS 3.1CRITICAL 9.8
TI-2021-18132 Improper authentication in Apache Shiro CVSS 3.1CRITICAL 9.8
TI-2022-14167 Authentication bypass in Apache Shiro CVSS 3.1CRITICAL 9.8
TI-2020-09649 Improper authentication in Apache Shiro CVSS 3.1CRITICAL 9.8
TI-2020-10910 Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass. CVSS 3.1HIGH 7.5

See all 24 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences