Auth bypass in Stackit Iaas API
CVE-2026-39910
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (39.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Stackit Iaas API — versions 0
Weakness classification (CWE)
References
- status.stackit.cloud (release-notes)
- www.vulncheck.com/advisories/stackit-iaas-api-privilege-escalation-via-service-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-39910?
- CVE-2026-39910 is a high-severity vulnerability in Stackit Iaas API, classified under Missing Authorization. CVSS score: 8.8/10. Published 2026-06-08.
- How severe is CVE-2026-39910?
- High severity. CVSS v3 base score is 8.8 out of 10.