Vulnerability in Himmelblau-Idm Himmelblau
CVE-2026-31979
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (7.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000
Affected products
- Himmelblau-Idm Himmelblau — versions >= 1.0.0, < 2.3.8, >= 3.0.0-alpha, < 3.1.0
Weakness classification (CWE)
References
- github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-44wm-q286-ghq3 (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-31979?
- CVE-2026-31979 is a high-severity vulnerability in Himmelblau-Idm Himmelblau, classified under Improper Link Resolution Before File Access. CVSS score: 8.8/10. Published 2026-03-11.
- How severe is CVE-2026-31979?
- High severity. CVSS v3 base score is 8.8 out of 10.