What is CVE-2026-31957?

CVE-2026-31957 is a critical-severity vulnerability in Himmelblau-idm Himmelblau, classified under Initialization of a Resource with an Insecure Default. CVSS score: 10.0/10. Published 2026-03-11.

How severe is CVE-2026-31957?

Critical severity. CVSS v3 base score is 10.0 out of 10.

RCE in Himmelblau-idm Himmelblau

CVE-2026-31957

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…

EPSS: 0.004 (58.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Himmelblau-idm Himmelblau — versions >= 3.0.0, < 3.1.0

Weakness classification (CWE)

CWE-1188 — Initialization of a Resource with an Insecure Default

References

https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-q746-m2wv-qh4v (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-31957?: CVE-2026-31957 is a critical-severity vulnerability in Himmelblau-idm Himmelblau, classified under Initialization of a Resource with an Insecure Default. CVSS score: 10.0/10. Published 2026-03-11.
How severe is CVE-2026-31957?: Critical severity. CVSS v3 base score is 10.0 out of 10.