{"id":"CVE-2026-40356","state":"PUBLISHED","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 NegoE","description":"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 unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message.","publishedAt":"2026-04-28T00:00:00.000Z","updatedAt":"2026-04-28T13:10:24.842Z","severity":{"score":5.9,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"mitre"},"assigner":"mitre","products":["MIT Kerberos 5"],"affected":[{"vendor":"MIT","product":"Kerberos 5","defaultStatus":"unaffected","versions":[{"version":"1.18","status":"affected","lessThan":"1.22.3","versionType":"custom"}]}],"references":["https://web.mit.edu/kerberos/advisories/","https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html","https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f"],"weaknesses":["CWE-191"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40356.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40356","state":"PUBLISHED","datePublished":"2026-04-28T00:00:00.000Z","dateUpdated":"2026-04-28T13:10:24.842Z","assignerShortName":"mitre","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateReserved":"2026-04-11T00:00:00.000Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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 unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message."}],"affected":[{"vendor":"MIT","product":"Kerberos 5","defaultStatus":"unaffected","versions":[{"version":"1.18","status":"affected","lessThan":"1.22.3","versionType":"custom"}]}],"references":[{"url":"https://web.mit.edu/kerberos/advisories/"},{"url":"https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html"},{"url":"https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f"}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-191","description":"CWE-191 Integer Underflow (Wrap or Wraparound)","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"mitre","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateUpdated":"2026-04-28T05:23:13.610Z"},"x_generator":{"engine":"enrichogram 0.0.1"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*","versionStartIncluding":"1.18","versionEndExcluding":"1.22.3"}]}]}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-28T13:10:05.740836Z","id":"CVE-2026-40356","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-28T13:10:24.842Z"}}]}}}