CVE-2026-39910 CRITICAL

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

Vendor Stackit
Product IaaS API
Weakness CWE-862 · Missing authorization
Published June 8, 2026
Last update June 9, 2026

CVSS base score

9.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

June 8, 2026 CVE published
June 9, 2026 Record updated