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.
CVE-2026-31957
This critical-severity CVE scores 10.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 10.0
- EG Score
- 10.0(low)
- EG Risk
- 50(Track)EG Risk 50/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity100% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 40%
- KEV
- Not listed
Published
March 11, 2026
Last Modified
June 17, 2026
Advisory Details (1)
Auto-updated Jul 27, 2026Unset domain configuration can allow any-tenant authentication at first login for remote deployments · Advisory · himmelblau-idm/himmelblau · GitHub
https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-q746-m2wv-qh4vWeakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 1× in last 7d / 1× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-27 13:41 UTCEG score recompute
Frequently asked(5)
What is CVE-2026-31957?
When was CVE-2026-31957 disclosed?
Is CVE-2026-31957 actively exploited?
What is the CVSS score of CVE-2026-31957?
How do I remediate CVE-2026-31957?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-31957
Is Your Infrastructure Affected by CVE-2026-31957?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.