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Fencer Vulns
high 8.8

CVE-2026-31979 json

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

published 2026-03-11 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-11332

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

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.

Patch / fix

  • himmelblau-idm himmelblau 2.3.8, 3.1.0
  • himmelblau SLE Module for Basesystem 15 SP7 2.3.9+git0.a9fd29b-150700.3.15.1
  • himmelblau SLES for SAP applications 16.0, SLES 16.0 2.3.8+git0.dec3693-160000.1.1

suse advisories SUSE-SU-2026:1361-1SUSE-FU-2026:20990-1

  • himmelblau openSUSE Leap 16.0 2.3.8+git0.dec3693-160000.1.1
  • himmelblau openSUSE Tumbleweed 2.3.8+git0.dec3693-1.1

opensuse advisories openSUSE-FU-2026:20453-1openSUSE-SU-2026:10328-1

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
7 mo ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-44wm-q286-ghq3 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • himmelblau-idm himmelblau

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.