CVE-2026-23901

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.

References

Affected packages

Git /

Affected ranges

Database specific

unresolved_ranges

[
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "fixed": "2.0.7"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "fixed": "2.0.7"
            }
        ]
    }
]

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23901.json"