# CVE-2026-31979

## Summary

- **CVE ID:** CVE-2026-31979
- **Severity:** HIGH
- **CVSS Score:** 8.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)
- **CWE:** CWE-59
- **Published:** Mar 11, 2026
- **Last Modified:** Mar 11, 2026

## Description

Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. Prior to 3.1.0 and 2.3.8, the himmelblaud-tasks daemon, running as root, writes Kerberos cache files under /tmp/krb5cc_<uid> without symlink protections. Since commit 87a51ee, PrivateTmp is explicitly removed from the tasks daemon's systemd hardening, exposing it to the host /tmp. A local user can exploit this via symlink attacks to chown or overwrite arbitrary files, achieving local privilege escalation. This vulnerability is fixed in 3.1.0 and 2.3.8.

## Affected Products

- himmelblau-idm — himmelblau (>= 1.0.0, < 2.3.8)
- himmelblau-idm — himmelblau (>= 3.0.0-alpha, < 3.1.0)

## References

- [CNA](https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-44wm-q286-ghq3)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.20%
- **EPSS Percentile:** 9.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._