CVE-2026-40355: CWE-476 NULL Pointer Dereference in MIT Kerberos 5
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.
AI Analysis
Technical Summary
CVE-2026-40355 is a vulnerability in MIT Kerberos 5 (krb5) prior to version 1.22.3 where a NULL pointer dereference can be triggered by calling gss_accept_sec_context() on systems that have a NegoEx mechanism registered in /etc/gss/mech. This flaw allows an unauthenticated remote attacker to cause a denial of service by crashing the process in the parse_nego_message function.
Potential Impact
The vulnerability results in a denial of service condition due to process termination caused by a NULL pointer dereference. There is no confidentiality or integrity impact reported. The attack requires network access but no privileges or user interaction.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch information is provided at this time. Until a patch is available, consider disabling the NegoEx mechanism if feasible to reduce exposure.
CVE-2026-40355: CWE-476 NULL Pointer Dereference in MIT Kerberos 5
Description
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 v3.1
Score 5.9medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-40355 is a vulnerability in MIT Kerberos 5 (krb5) prior to version 1.22.3 where a NULL pointer dereference can be triggered by calling gss_accept_sec_context() on systems that have a NegoEx mechanism registered in /etc/gss/mech. This flaw allows an unauthenticated remote attacker to cause a denial of service by crashing the process in the parse_nego_message function.
Potential Impact
The vulnerability results in a denial of service condition due to process termination caused by a NULL pointer dereference. There is no confidentiality or integrity impact reported. The attack requires network access but no privileges or user interaction.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch information is provided at this time. Until a patch is available, consider disabling the NegoEx mechanism if feasible to reduce exposure.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-04-11T00:00:00.000Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69f043f9cbff5d8610b6611c
Added to database: 04/28/2026, 05:22:01 UTC
Last enriched: 07/15/2026, 11:23:12 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 127
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