Vulnerability in Apache Tomcat
CVE-2026-43513
Improper Handling of Case Sensitivity vulnerability in LockOutRealm in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.0.M1 through 9.0.117, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Older unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (41.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Apache Tomcat
- Apache Software Foundation Tomcat — versions 11.0.0-M1, 10.1.0-M1, 9.0.0.M1
Weakness classification (CWE)
References
- lists.apache.org/thread/ytjcgldshj73lcnd1sh95od5hrghwogp (vendor-advisory, Mailing List, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-43513?
- CVE-2026-43513 is a high-severity vulnerability in Apache Tomcat, classified under Improper Handling of Case Sensitivity. CVSS score: 7.5/10. Published 2026-05-12.
- How severe is CVE-2026-43513?
- High severity. CVSS v3 base score is 7.5 out of 10.