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Ubuntu Tomcat Important Denial Of Service Remote Code Issues 8450-1

ubuntu
Calendar Grey June 18, 2026
Dist Ubuntu Esm H88
Several critical issues in Tomcat on Ubuntu were fixed to prevent potential remote attacks and denial of service.
Several security issues were fixed in Tomcat.

Summary

Several security issues were fixed in Tomcat.

Software Description:

- tomcat11: Servlet and JSP engine

Details:

It was discovered that Tomcat did not properly limit the size of

WebDAV LOCK and PROPFIND request bodies. A remote attacker could

possibly use this issue to cause Tomcat to consume excessive memory,

resulting in a denial of service. (CVE-2026-41284)

It was discovered that Tomcat incorrectly validated HTTP/2 header

fields. A remote attacker could use this issue to cause Tomcat to

crash or possibly execute arbitrary code. (CVE-2026-41293)

It was discovered that Tomcat did not properly clear HTTP

authentication headers during WebSocket connection upgrades and

redirects. A remote attacker could possibly use this issue to obtain

sensitive credentials. (CVE-2026-42498)

It was discovered that Tomcat incorrectly handled authorization

when multiple method constraints defined the same HTTP method. A

remote attacker could possibly use this issue to bypass

authorization restric...

Read the Full Advisory

Topics%20covered

Topics Covered

security advisory denial of service critical remote access Ubuntu authentication issue

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 26.04 LTS
  libtomcat11-embed-java          11.0.18-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro
  libtomcat11-java                11.0.18-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro
  tomcat11                        11.0.18-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro

After a standard system update you need to restart Tomcat to make
all the necessary changes.

References

https://ubuntu.com/security/notices/USN-8450-1

CVE-2026-41284, CVE-2026-41293, CVE-2026-42498, CVE-2026-43515

Severity
critical
Lowest
Low
Medium
High
Critical

Ubuntu Security Notice USN-8450-1

Topics%20covered

Topics Covered

security advisory denial of service critical remote access Ubuntu authentication issue

Package Information

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