Vulnerability DatabaseCVE-2026-40356
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CVE-2026-40356
Published:April 28, 2026
Updated:May 18, 2026
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.
Affected Packages
https://github.com/krb5/krb5.git (GITHUB):
Affected version(s) >=krb5-1.0-alpha0 <krb5-1.22.3-final
Fix Suggestion:
Update to version krb5-1.22.3-final
Related Resources (3)
https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html
https://web.mit.edu/kerberos/advisories/
https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f
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CVSS v4
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Integer Underflow (Wrap or Wraparound)
CWE-191
EPSS
Base Score:
0.10