CVE-2026-40355

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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.6% chance of exploitation in the next 30 days; higher than 50% of CVEs (scores of 2026-10-25)

CWE

CWE-476

Published

2026-04-28

Modified

2026-10-15

Record from

the NVD, synced 2026-10-19

Affected

• mit:kerberos_5

References

• https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html
• https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f
• https://web.mit.edu/kerberos/advisories/
• https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html
• https://cert-portal.siemens.com/productcert/html/ssa-019113.html

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