CVE-2026-23901
Fixed in a distro release EPSS <1%CVSS 1.0
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.
Products: Apache Software Foundation Apache Shiro
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Maven | org.apache.shiro:shiro-core | 2.1.0 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | apache-activemq-5.19 | no fix |
| Chainguard | apache-activemq-6.1 | no fix |
| Chainguard | apache-activemq-fips-5.19 | no fix |
| Chainguard | apache-activemq-fips-6.1 | no fix |
| Chainguard | apache-jena-fuseki | 6.0.0-r2 |
| Chainguard | datahub-frontend | no fix |
| Chainguard | neo4j-2025.08 | no fix |
| Chainguard | neo4j-2025.10 | no fix |
| Chainguard | neo4j-2025.11 | no fix |
| Chainguard | neo4j-2025.12 | no fix |
| Chainguard | neo4j-2026.01 | 2026.01.4-r0 |
| Chainguard | neo4j-4.4 | no fix |
| Chainguard | neo4j-5.26 | 5.26.21-r2 |
| Chainguard | opensearch-2-identity-shiro | no fix |
| Debian 12 | shiro | no fix |
| Debian 13 | shiro | no fix |
| Debian 14 | shiro | no fix |
| Ubuntu 20.04 LTS | shiro | no fix |
| Ubuntu 22.04 LTS | shiro | no fix |
| Ubuntu 25.10 | shiro | no fix |
| Ubuntu 26.04 LTS | shiro | no fix |
| Ubuntu 26.10 | shiro | no fix |
| Ubuntu Pro 16.04 LTS | shiro | no fix |
| Ubuntu Pro 18.04 LTS | shiro | no fix |
| Ubuntu Pro 24.04 LTS | shiro | no fix |
| Wolfi | neo4j-2025.10 | no fix |
| Wolfi | neo4j-2025.12 | no fix |
| Wolfi | neo4j-2026.01 | 2026.01.4-r0 |