CVE-2026-23901
Apache Shiro Affected by an Observable Timing Discrepancy Vulnerability
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | org.apache.shiro:shiro-core | < 2.1.0 | 2.1.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Apache | Shiro | before 2.0.7 |