Home / mailings [SECURITY] [DSA 6293-1] krb5 security update
Posted on 22 May 2026
Debian Security Advisory- -------------------------------------------------------------------------
Debian Security Advisory DSA-6293-1 security@debian.org
https://www.debian.org/security/ Salvatore Bonaccorso
May 22, 2026 https://www.debian.org/security/faq
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Package : krb5
CVE ID : CVE-2026-40355
Debian Bug : 1135317
Cem Onat Karagun discovered two vulnerabilities in the NegoEx parsing in
krb5, the MIT implementation of Kerberos. An unauthenticated remote
attacker can take advantage of these flaws to cause a denial of service.
For the oldstable distribution (bookworm), this problem has been fixed
in version 1.20.1-2+deb12u5.
For the stable distribution (trixie), this problem has been fixed in
version 1.21.3-5+deb13u1.
We recommend that you upgrade your krb5 packages.
For the detailed security status of krb5 please refer to its security
tracker page at:
https://security-tracker.debian.org/tracker/krb5
Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/
Mailing list: debian-security-announce@lists.debian.org
