PT-2026-35666 · Mit · Kerberos 5

Published 2026-04-28 · Updated 2026-04-28 · CVE-2026-40356

Mitre

CVSS v3.1

5.9

Medium

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

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.

Fix

Integer Underflow

Weakness Enumeration

CWE-191

Related Identifiers

CVE-2026-40356

Affected Products

Kerberos 5

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-40356 · Security Note
• https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f · Note
• https://web.mit.edu/kerberos/advisories · Note
• https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html · Note