PT-2026-35656 · Mit+1 · Mit Kerberos 5+1

Cem Onat Karagun · Published 2026-04-28 · Updated 2026-06-03 · CVE-2026-40355

Positive Technologies (AI Summary)

CVSS v3.1

5.9

Medium

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions MIT Kerberos 5 versions prior to 1.22.3

Description A NULL pointer dereference occurs when an application calls the gss accept sec context() function on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this condition, leading to process termination within the parse nego message() function.

Recommendations Update to version 1.22.3 or later.

Exploit

Fix

DoS

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

ALSA-2026:16799

ALSA-2026:19145

ALSA-2026:19357

CVE-2026-40355

ECHO-3921-9F59-F2E1

OESA-2026-2257

OPENSUSE-SU-2026:10729-1

RHSA-2026:12220

RHSA-2026:16799

RHSA-2026:19145

RHSA-2026:19357

Affected Products

Mit Kerberos 5

Rocky Linux

References · 41

• 🔥 https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html · Exploit
• https://ubuntu.com/security/CVE-2026-40355 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:10729-1 · Vendor Advisory
• https://osv.dev/vulnerability/ALSA-2026:19145 · Vendor Advisory
• https://errata.rockylinux.org/RLSA-2026:16799 · Vendor Advisory
• https://errata.rockylinux.org/RLSA-2026:19357 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2026-16799.html · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-40355 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-40355 · Vendor Advisory
• https://osv.dev/vulnerability/ROOT-OS-DEBIAN-12-CVE-2026-40355 · Vendor Advisory
• https://osv.dev/vulnerability/ROOT-OS-DEBIAN-13-CVE-2026-40355 · Vendor Advisory
• https://errata.almalinux.org/10/ALSA-2026-19145.html · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-40355 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-40356 · Security Note
• https://osv.dev/vulnerability/ALSA-2026:19357 · Vendor Advisory