# CVE-2026-39910: STACKIT IaaS API Privilege Escalation via Service Account Attachment

> Low-privileged attackers can escalate to full organization control by attaching high-privileged service accounts to VMs via an unvalidated API endpoint.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Jun 2026
- **Updated:** 24 Aug 2026
- **Also known as:** GHSA-p35h-r99r-9fcm

## What is CVE-2026-39910?

CVE-2026-39910 is a high-severity missing authorization vulnerability in STACKIT IaaS API, published on 8 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

STACKIT IaaS API contains a missing authorization check vulnerability that allows authenticated, low-privileged attackers to escalate privileges to full organization compromise by attaching arbitrary service accounts to virtual machines they control. Attackers can exploit the unvalidated PUT servers service-accounts endpoint to attach high-privileged service accounts and query the Instance Metadata Service to retrieve OAuth2 tokens, bypassing tenant boundaries and gaining unauthorized control over the entire organization environment.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-39910?


## How do I fix CVE-2026-39910?

No fix has been published for CVE-2026-39910 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-39910 being exploited?

There is no known exploitation of CVE-2026-39910 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-39910 and fix it if it is affected.

What it is: CVE-2026-39910 is a high-severity missing authorization vulnerability in STACKIT IaaS API, published on 8 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-39910 in the wild and no public exploit code.

Affected product: STACKIT IaaS API. 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-2026-39910/ (Markdown: https://insights.sbomify.com/CVE-2026-39910/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-39910
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39910
- OSV: https://osv.dev/vulnerability/CVE-2026-39910

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-39910/
Summaries are generated and may contain mistakes; the official description above is the record.