TI-2026-24522 Aliases CVE-2026-31979

himmelblaud-tasks: local privilege escalation via /tmp symlink attack on Kerberos ccache

HIGH 73CWE-59Published 2026-03-11 · Updated 2026-03-11

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00232 14th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed himmelblau (himmelblau-idm): 2.3.8, 3.1.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
himmelblau-idm	himmelblau	1.0.0 to before 2.3.8; 3.0.0-alpha to before 3.1.0	2.3.8, 3.1.0	Patch available	CNA

himmelblau Vendorhimmelblau-idm Affected 1.0.0 to before 2.3.8; 3.0.0-alpha to before 3.1.0 Fixed in 2.3.8, 3.1.0 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:himmelblau-idm:himmelblau::::::::	1.0.0 to before 2.3.8; 3.0.0 to before 3.1.0	Vulnerable	himmelblau-idm

cpe:2.3:a:himmelblau-idm:himmelblau:*:*:*:*:*:*:*:* Versions 1.0.0 to before 2.3.8; 3.0.0 to before 3.1.0 Vulnerable ·himmelblau-idm

Remediation

Fix · CNA himmelblau (himmelblau-idm) Fixed in 2.3.8, 3.1.0

Timeline

2026-10-02 Threatist record created from CVE-2026-31979

References

Exploit 1

https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-44wm-q286-ghq3

TI-2026-26683 himmelblau: NSS fake-primary group lookup reintroduces name collision risk CVSS 3.1HIGH 7.0
TI-2025-34616 Himmelblau's Kerberos credential cache collection is world readable CVSS 3.1HIGH 7.1
TI-2026-24501 Himmelblau unset domain configuration can allow any-tenant authentication at first login for remote deployments CVSS 3.1CRITICAL 10.0

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences