Severity: low Affected versions:
- Apache Shiro (org.apache.shiro:shiro-core) before 2.0.7 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. Credit: 4ra1n (finder) Y4tacker (finder) lprimak (remediation developer) References: https://shiro.apache.org/ https://www.cve.org/CVERecord?id=CVE-2026-23901
