{"id":"CVE-2026-31957","state":"PUBLISHED","title":"Himmelblau unset domain configuration can allow any-tenant authentication at first login for remote deployments","description":"Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. From 3.0.0 to before 3.1.0, if Himmelblau is deployed without a configured tenant domain in himmelblau.conf, authentication is not tenant-scoped. In this mode, Himmelblau can accept authentication attempts for arbitrary Entra ID domains by dynamically registering providers at runtime. This behavior is intended for initial/local bootstrap scenarios, but it can create risk in remote authentication environments. This vulnerability is fixed in 3.1.0.","publishedAt":"2026-03-11T19:25:21.230Z","updatedAt":"2026-03-12T20:00:41.000Z","severity":{"score":10,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["himmelblau-idm himmelblau"],"affected":[{"vendor":"himmelblau-idm","product":"himmelblau","versions":[{"version":">= 3.0.0, < 3.1.0","status":"affected"}]}],"references":["https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-q746-m2wv-qh4v"],"weaknesses":["CWE-1188"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31957.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31957","state":"PUBLISHED","datePublished":"2026-03-11T19:25:21.230Z","dateUpdated":"2026-03-12T20:00:41.000Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-10T15:40:10.480Z"},"containers":{"cna":{"title":"Himmelblau unset domain configuration can allow any-tenant authentication at first login for remote deployments","descriptions":[{"lang":"en","value":"Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. From 3.0.0 to before 3.1.0, if Himmelblau is deployed without a configured tenant domain in himmelblau.conf, authentication is not tenant-scoped. In this mode, Himmelblau can accept authentication attempts for arbitrary Entra ID domains by dynamically registering providers at runtime. This behavior is intended for initial/local bootstrap scenarios, but it can create risk in remote authentication environments. This vulnerability is fixed in 3.1.0."}],"affected":[{"vendor":"himmelblau-idm","product":"himmelblau","versions":[{"version":">= 3.0.0, < 3.1.0","status":"affected"}]}],"references":[{"url":"https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-q746-m2wv-qh4v","name":"https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-q746-m2wv-qh4v","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":10,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1188","lang":"en","description":"CWE-1188: Insecure Default Initialization of Resource","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-11T19:25:21.230Z"},"source":{"advisory":"GHSA-q746-m2wv-qh4v","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-12T20:00:34.426187Z","id":"CVE-2026-31957","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-12T20:00:41.000Z"}}]}}}