USN-8585-1: Kerberos vulnerabilities

Publication date

22 July 2026

Overview

Several security issues were fixed in Kerberos.


Packages

  • 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)

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)

Update instructions

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

Learn more about how to get the fixes.

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


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