CVE-2026-42498
High
Description
Exposure of HTTP Authentication Header to unexpected hosts during WebSocket authentication vulnerability 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 9.0.2 through 9.0.117, from 8.5.24 through 8.5.100, from 7.0.83 through 7.0.109. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118, which fix the issue.
SeverityHigh
CVSS7.3
Exploit probability—
Product
Apache Tomcat
PublishedMay 12, 2026
First seenMay 12, 2026
Weakness typeCWE-200Sensitive information exposure
How to fix
Update
- apache tomcat9.0.118, 10.1.55, 11.0.22 or later
- org.apache.tomcat.embed:tomcat-embed-core9.0.118, 10.1.55, 11.0.22 or later
- org.apache.tomcat:tomcat9.0.118, 10.1.55, 11.0.22 or later
- org.apache.tomcat:tomcat-catalina9.0.118, 10.1.55, 11.0.22 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| apache tomcat | 7.0.0 ≤ v ≤ 7.0.109, 8.5.0 ≤ v ≤ 8.5.100, 9.0.0 ≤ v < 9.0.118, 10.1.0 ≤ v < 10.1.55, 11.0.0 ≤ v < 11.0.22 | 9.0.118, 10.1.55, 11.0.22 |
| org.apache.tomcat.embed:tomcat-embed-coreMaven | v < 9.0.118, 10.1.0-M1 ≤ v < 10.1.55, 11.0.0-M1 ≤ v < 11.0.22 | 9.0.118, 10.1.55, 11.0.22 |
| org.apache.tomcat:tomcatMaven | v < 9.0.118, 10.1.0-M1 ≤ v < 10.1.55, 11.0.0-M1 ≤ v < 11.0.22 | 9.0.118, 10.1.55, 11.0.22 |
| org.apache.tomcat:tomcat-catalinaMaven | v < 9.0.118, 10.1.0-M1 ≤ v < 10.1.55, 11.0.0-M1 ≤ v < 11.0.22 | 9.0.118, 10.1.55, 11.0.22 |
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