# CVE-2026-31979: himmelblaud-tasks: local privilege escalation via /tmp symlink attack on Kerberos ccache

> A local attacker can exploit a symlink vulnerability in the himmelblaud-tasks daemon to overwrite arbitrary files and escalate privileges to root.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Mar 2026
- **Updated:** 11 Mar 2026
- **Also known as:** GHSA-44wm-q286-ghq3, openSUSE-SU-2026:10328-1

## What is CVE-2026-31979?

CVE-2026-31979 is a high-severity path traversal vulnerability in himmelblau-idm himmelblau, published on 11 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### 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.

Weakness: CWE-59 (Improper Link Resolution Before File Access)

## Which versions are affected by CVE-2026-31979?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `himmelblau` | openSUSE:Tumbleweed | All versions | 2.3.8+git0.dec3693-1.1 |

Products: Himmelblau-Idm Himmelblau.

## How do I fix CVE-2026-31979?

Upgrade to a fixed version.

## Is CVE-2026-31979 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31979 exists.

## Other vulnerabilities in himmelblau-idm himmelblau

- [CVE-2026-31957](https://insights.sbomify.com/CVE-2026-31957/): Himmelblau unset domain configuration can allow any-tenant authentication at first login for remote deployments (critical 10.0)
- [CVE-2025-54882](https://insights.sbomify.com/CVE-2025-54882/): Himmelblau's Kerberos credential cache collection is world readable (high 7.1)
- [CVE-2026-34397](https://insights.sbomify.com/CVE-2026-34397/): himmelblau: NSS fake-primary group lookup reintroduces name collision risk (medium 6.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31979 and fix it if it is affected.

What it is: CVE-2026-31979 is a high-severity path traversal vulnerability in himmelblau-idm himmelblau, published on 11 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31979 exists.

Affected product: himmelblau-idm himmelblau. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-31979/ (Markdown: https://insights.sbomify.com/CVE-2026-31979/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31979
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31979
- OSV: https://osv.dev/vulnerability/CVE-2026-31979

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31979/
Summaries are generated and may contain mistakes; the official description above is the record.