Ubuntu 26.04 LTS : Tomcat vulnerabilities (USN-8450-1)

critical Nessus Plugin ID 321761

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8450-1 advisory.

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 restrictions. (CVE-2026-43515)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

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

Plugin Details

Severity: Critical

ID: 321761

File Name: ubuntu_USN-8450-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 6/20/2026

Updated: 6/20/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-41293

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:tomcat11-common, p-cpe:/a:canonical:ubuntu_linux:libtomcat11-java, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:tomcat11-user, p-cpe:/a:canonical:ubuntu_linux:tomcat11-admin, p-cpe:/a:canonical:ubuntu_linux:tomcat11-examples, p-cpe:/a:canonical:ubuntu_linux:libtomcat11-embed-java, p-cpe:/a:canonical:ubuntu_linux:tomcat11

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/18/2026

Vulnerability Publication Date: 5/5/2026

Reference Information

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

IAVA: 2026-A-0475

USN: 8450-1