SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-31979

Since commit 87a51ee, PrivateTmp is explicitly removed from the tasks daemon's systemd hardening, exposing it to the host /tmp.

HIGH 7.8EPSS 0.20%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.20%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.20% probability · 9th percentile
CISA KEV
Not listed
Weakness
CWE-59
Affected
himmelblau-idm/himmelblau
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.