Threat Intelligence / CVE / CVE-2026-31979

CVE-2026-31979 — Himmelblau-Idm Himmelblau

CVSS v3.1 7.5 (HIGH) · EPSS 0.0% (higher than 6.6% of all scored CVEs) · Priority 4/10 · Published 2026-03-11

As of 2026-03-16, CVE-2026-31979 is a HIGH-severity vulnerability in Himmelblau-Idm Himmelblau, CVSS v3.1 7.5, EPSS 0.0% (6.6th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-31979, most recently “CVE-2026-31979: Himmelblau Root Privilege Escalation via Symlink Attack on Kerberos Cache”.

Last updated: 2026-03-16

What is CVE-2026-31979?

CVE-2026-31979 is a high-severity local privilege escalation vulnerability in Himmelblau, an open-source Azure Entra ID authentication and Intune compliance suite for Linux. The vulnerability resides in the himmelblaud-tasks daemon which runs as root. The root cause traces to commit 87a51ee which removed PrivateTmp from the tasks daemon's systemd hardening, exposing it to the host's /tmp directory without symlink protections. Four compounding factors enable exploitation: PrivateTmp removal, directory creation following symlinks via DirBuilder without validation, file writes lacking O_NOFOLLOW flags, and an insecure hardcoded ccache path at /tmp/krb5cc_. An unprivileged local user can create a symbolic link at the ccache path pointing to /etc, causing the root-privileged daemon to chown /etc to the attacker, enabling full root access. Affects versions 1.0.0 through 3.0.1, patched in 3.1.0 and 2.3.8.

The record classifies CVE-2026-31979 under weakness classes CWE-59, CWE-61. Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 186 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 7.5 — HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS (FIRST): 0.0% probability of exploitation in the next 30 days, higher than 6.6% of all scored CVEs
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2026-03-11, last modified 2026-03-16

Is CVE-2026-31979 being exploited?

It currently carries a trending score of 7 in the Threadlinqs vulnerability feed.

Affected products and versions

Himmelblau-Idm: Himmelblau

How to fix CVE-2026-31979

Vendor advisory: https://github.com/himmelblau-idm/himmelblau/security/advisories/GHSA-44wm-q286-ghq3. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2026-31979

1 tracked threat in the Threadlinqs corpus references CVE-2026-31979, either in the campaign’s CVE list or as an indicator on the campaign record.

CVE-2026-31979: Himmelblau Root Privilege Escalation via Symlink Attack on Kerberos Cache — HIGH · 2026-03-20

Sources

Seeded from threat-derived and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

github.com

Full detection coverage & IOCs for threats exploiting CVE-2026-31979 are available via the Threadlinqs MCP server (Purple tier). View plans →

← all vulnerabilities · Markdown version · Threadlinqs Intelligence