CVE-2026-42498
HIGH7.3EPSS 0.05%Apache Tomcat - WebSocket authentication header exposure
Published: 5/12/2026Modified: 5/19/2026
Description
Versions Affected: Apache Tomcat 11.0.0-M1 to 11.0.21 Apache Tomcat 10.1.0-M1 to 10.1.54 Apache Tomcat 9.0.2 to 9.0.117 Older, unsupported versions may also be affected Description: If a WebSocket request was redirected after authentication, Tomcat's WebSocket client would present the most recent authentication header to the redirect target host. Mitigation: Users of the affected versions should apply one of the following mitigations: - Upgrade to Apache Tomcat 11.0.22 or later - Upgrade to Apache Tomcat 10.1.55 or later - Upgrade to Apache Tomcat 9.0.118 or later Credit: This issue was identified by lokerxx
Affected packages (7)
- Bitnami/tomcat>= 10.0.0, < 10.1.55, >= 11.0.0, < 11.0.22, >= 9.0.0, < 9.0.118
- Debian/tomcat10from 0
- Debian/tomcat11from 0
- Debian/tomcat9from 0, < 9.0.70-2
- Maven/org.apache.tomcat.embed:tomcat-embed-corefrom 0, < 9.0.118
- Maven/org.apache.tomcat:tomcatfrom 0, < 9.0.118
- Maven/org.apache.tomcat:tomcat-catalinafrom 0, < 9.0.118
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
References (11)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-42498
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-42498
- PATCHhttps://github.com/apache/tomcat
- WEBhttps://github.com/apache/tomcat/commit/169d725788ea6aec217ecac70fe4161c837ba423
- WEBhttps://github.com/apache/tomcat/commit/6cbe274592ef2d11607b5b188e1df649de52f8d5
- WEBhttps://github.com/apache/tomcat/commit/b7b173694d588ddcfa432f079baf763cbbbaa5c4
- WEBhttps://lists.apache.org/thread/n61zwf75jrv09rz90j4jssncm244bwdb
- WEBhttps://tomcat.apache.org/security-10.html
- WEBhttps://tomcat.apache.org/security-11.html
- WEBhttps://tomcat.apache.org/security-9.html
- WEBhttp://www.openwall.com/lists/oss-security/2026/05/12/14