Debian alert DLA-4603-1 (krb5)

From:
             
 
Emmanuel Arias <eamanu@debian.org>
To:
             
 
debian-lts-announce@lists.debian.org
Subject:
             
 
[SECURITY] [DLA 4603-1] krb5 security update
Date:
             
 
Thu, 28 May 2026 08:35:55 -0300
Message-ID:
             
 
<ahgomzUF9osNXCYk@debian>
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Debian LTS Advisory DLA-4603-1                debian-lts@lists.debian.org
https://www.debian.org/lts/security/                       Emmanuel Arias
May 28, 2026                                  https://wiki.debian.org/LTS
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Package        : krb5
Version        : 1.18.3-6+deb11u8
CVE ID         : CVE-2026-40355 CVE-2026-40356
Debian Bug     : 1135317

Two vulnerabilities was found in krb5, the MIT implementation of Kerberos, that
an unauthenticated remote attacker can take advantage of these vulnerabilities
to cause a denial of service.

CVE-2026-40355

    If an application calls gss_accept_sec_context() on a system with a NegoEx
    mechanism registered in /etc/gss/mech, an unauthenticated remote attacker
    can trigger a null pointer dereference, causing the process to terminate.

CVE-2026-40356

    If an application calls gss_accept_sec_context() on a system with a NegoEx
    mechanism registered in /etc/gss/mech, an unauthenticated remote attacker
    can trigger a read overrun of up to 52 bytes, possibly causing the process
    to terminate. Exfiltration of the bytes read does not appear possible.

For Debian 11 bullseye, these problems have been fixed in version
1.18.3-6+deb11u8.

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 LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS


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