Ubuntu 26.04 LTS Kerberos Important DoS Issues USN-8585-1 CVE-2026

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Several security issues were fixed in Kerberos. Software Description: - krb5: MIT Kerberos Network Authentication Protocol Details: It was discovered that Kerberos had an integer underflow vulnerability in the berval2tl_data() function. An attacker could possibly use this issue to cause Kerberos to crash, resulting in a denial of service. (CVE-2026-11850) It was discovered that Kerberos had vulnerabilities in its NegoEx mechanism parsing. A remote attacker could possibly use these issues to cause Kerberos to crash, resulting in a denial of service. (CVE-2026-40355, CVE-2026-40356)

Several security issues were fixed in Kerberos.

Software Description:

- krb5: MIT Kerberos Network Authentication Protocol

It was discovered that Kerberos had an integer underflow vulnerability

in the berval2tl_data() function. An attacker could possibly use this issue

to cause Kerberos to crash, resulting in a denial of service.

It was discovered that Kerberos had vulnerabilities in its NegoEx mechanism

parsing. A remote attacker could possibly use these issues to cause

Kerberos to crash, resulting in a denial of service. (CVE-2026-40355,

The problem can be corrected by updating your system to the following package versions: Ubuntu 26.04 LTS krb5-admin-server 1.22.1-2ubuntu4.1 krb5-kdc 1.22.1-2ubuntu4.1 libkrb5-3 1.22.1-2ubuntu4.1 Ubuntu 24.04 LTS krb5-admin-server 1.20.1-6ubuntu2.7 krb5-kdc 1.20.1-6ubuntu2.7 libkrb5-3 1.20.1-6ubuntu2.7 Ubuntu 22.04 LTS krb5-admin-server 1.19.2-2ubuntu0.8 krb5-kdc 1.19.2-2ubuntu0.8 libkrb5-3 1.19.2-2ubuntu0.8 After a standard system update you need to restart Kerberos to make all the necessary changes.

CVE-2026-11850, CVE-2026-40355, CVE-2026-40356

Ubuntu Security Notice USN-8585-1

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