CVE-2026-23901Apache Shiro: Brute force attack possible to determine valid user names
Updated under an hour ago ()
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It affects Apache Software Foundation Apache Shiro and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
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.
- CVSS
- 1.0 LOW (v4.0, CNA)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
- Weakness (CWE)
- CWE-208
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- apache
- NVD analysis
- Analyzed
- Record last updated
- Feb 10, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Apache Software Foundation Apache Shiro apache_software_foundation:apache_shiro (from the name) | before 2.0.7 | CNA record |
apache shiro apache:shiro | before 2.0.7 | NVD |
References
- https://lists.apache.org/thread/mm1jct9b86jvnh3y44tj22xvjtx3xhhhvendor-advisory, issue-tracking, mailing-list, third-party-advisory
- http://www.openwall.com/lists/oss-security/2026/02/08/2mailing-list, third-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.