Integer Underflow Affecting krb5 package, versions <1.22.1-2.1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.6% (46th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-DEBIANUNSTABLE-KRB5-16334225
  • published1 May 2026
  • disclosed28 Apr 2026

Introduced: 28 Apr 2026

CVE-2026-40356  (opens in a new tab)
CWE-191  (opens in a new tab)

How to fix?

Upgrade Debian:unstable krb5 to version 1.22.1-2.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream krb5 package and not the krb5 package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read 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 this, possibly causing the process to terminate in parse_message.

CVSS Base Scores

version 3.1