{"id":"CVE-2026-40355","title":"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","summary":"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 trig…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"mit","product":"kerberos_5","affected":["kerberos_5 >= 1.18.0, <= 1.22.2"],"published":"2026-04-28","updated":"2026-07-08","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-40355","references":[{"url":"https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html","label":"cve@mitre.org"},{"url":"https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f","label":"cve@mitre.org"},{"url":"https://web.mit.edu/kerberos/advisories/","label":"cve@mitre.org"},{"url":"https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","cve.org","exploit-available"],"epss":0.00611,"epssPercentile":0.47588,"ingestedAt":"2026-07-08T12:51:00.642Z","exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-04-28T12:53:15.785781Z"},"slug":"CVE-2026-40355","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `kerberos_5 >= 1.18.0, <= 1.22.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":5173,"id":"CVE-2026-40355","ts":1788887251459,"field":"exploit_available","old":"false","new":"true"},{"seq":4056,"id":"CVE-2026-40355","ts":1788886367395,"field":"exploit_available","old":"true","new":"false"},{"seq":2847,"id":"CVE-2026-40355","ts":1788883034008,"field":"exploit_available","old":"false","new":"true"},{"seq":1876,"id":"CVE-2026-40355","ts":1788882436916,"field":"exploit_available","old":"true","new":"false"},{"seq":313,"id":"CVE-2026-40355","ts":1788881649920,"field":"exploit_available","old":"false","new":"true"}]}