{"id":"CVE-2026-40356","title":"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","summary":"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 unauthenticat…","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-191"],"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-2026-40356","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"}],"tags":["nvd"],"epss":0.00604,"epssPercentile":0.47581,"ingestedAt":"2026-07-08T12:51:00.671Z","slug":"CVE-2026-40356","body":"## Overview\n\nIn 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.\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":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}