{"id":"CVE-2026-31957","summary":"Himmelblau unset domain configuration can allow any-tenant authentication at first login for remote deployments","details":"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.","aliases":["GHSA-q746-m2wv-qh4v"],"modified":"2026-04-01T23:10:16.237505Z","published":"2026-03-11T19:25:21.230Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-1188"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31957.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31957.json"},{"type":"ADVISORY","url":"https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-q746-m2wv-qh4v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31957"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/himmelblau-idm/himmelblau","events":[{"introduced":"f6b4beed26b55d02a81fb064b0a21fb059aa99fe"},{"fixed":"9079a98b44beb1c4e77215a262b95e6fd44c1dfb"}]}],"versions":["3.0.0","3.0.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31957.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"}]}