Vulnerability · Published Mar 11, 2026 · Assigned by GitHub_M
CVE-2026-31979himmelblaud-tasks: local privilege escalation via /tmp symlink attack on Kerberos ccache
High 8.8
In plain English
A high-severity security flaw in himmelblau from himmelblau-idm. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities).
Official 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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| himmelblau-idm | himmelblau | >= 1.0.0, < 2.3.8>= 3.0.0-alpha, < 3.1.0 |
Weakness: CWE-59 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H