CVE-2026-40355CWE-476

CVE-2026-40355

Medium · published April 28, 2026

CVSS v3.1
5.9
EPSS
1%
Percentile
57.7
In the wild
Unconfirmed
What it is

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference 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, causing the process to terminate in parse_nego_message.

The record
Technical detail
CVSS v3.1
5.9 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00847 · 57.7th percentile
Weakness
CWE-476 · NULL Pointer Dereference
Published
2026-04-28T10:16Z
Affected products (1)
ProductVersionsFixed in
mit/kerberos_5≥ 1.18.0, ≤ 1.22.2—
References (7)
https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html · [email protected]https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f · [email protected]https://web.mit.edu/kerberos/advisories/ · [email protected]https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html · 134c704f-9b21-4f2e-91b3-4a467353bcc0https://cert-portal.siemens.com/productcert/html/ssa-019113.html · 0b142b55-0307-4c5a-b3c9-f314f3fb7c5ehttps://cert-portal.siemens.com/productcert/html/ssa-082556.html · 0b142b55-0307-4c5a-b3c9-f314f3fb7c5ehttps://cert-portal.siemens.com/productcert/html/ssa-457936.html · 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
EPSS history
Timeline
  • 28 APR 00:00Z
    In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx…
    cvelistv5