Vulnerability in Apache Shiro
CVE-2026-43827
Default configurations of Apache Shiro have a session fixation vulnerability. This issue affects Apache Shiro from 1.0 to 2.1.0, and 3.0.0-alpha-1. Users are recommended to upgrade to version 2.1.1, or 3.0.0-alpha-2 or later, which fixes the issue. In the affected versions, when a session already exists, it is not invalidated upon successful login, nor is a new session being generated with a new ID.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (43.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Apache Shiro — versions 3.0.0
- Apache Software Foundation Shiro — versions 1.0, 3.0.0-alpha-0
Weakness classification (CWE)
References
- shiro.apache.org/security-reports.html (vendor-advisory, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-43827?
- CVE-2026-43827 is a medium-severity vulnerability in Apache Shiro, classified under Session Fixation. CVSS score: 6.5/10. Published 2026-05-25.
- How severe is CVE-2026-43827?
- Medium severity. CVSS v3 base score is 6.5 out of 10.