Skip to main content
← All vulnerabilities
CVE-2026-23901GHSA-C4QC-4Q9P-M9Q9

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

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 2.0.7, 2.1.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • org.apache.shiro:shiro-core

    fixed in 2.0.7

  • org.apache.shiro:shiro-coreMaven

    fixed in 2.1.0

References 1

lists.apache.org