CVE-2026-39910 json
STACKIT IaaS API Privilege Escalation via Service Account Attachment
published 2026-06-08 5 mo ago modified 2026-10-30 10 d ago also EUVD-2026-35128
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 15%
- public exploits
- 0
- none known
Summary
STACKIT IaaS API contains a missing authorization check in the PUT servers service-accounts endpoint. An authenticated, low-privileged attacker can attach an arbitrary service account to a virtual machine they control without validation of their permission to use it, then query the Instance Metadata Service (IMDS) to retrieve an OAuth2 token for that service account and act with its privileges. The impact is confined to the attacker’s own project. The STACKIT Identity Provider enforces strict project matching between the target VM and the requested service account during token impersonation, so cross-project and cross-organization exploitation is not possible. Any further access is bounded by the IAM roles already assigned to the targeted service account.
Patch / fix
- STACKIT IaaS API 2026-05-28
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 5 mo ago
Exploit prediction
0.25% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.7 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 7.7 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- STACKIT IaaS API
Classification
- Weakness
-
- CWE-862 Missing Authorization
References
-
status.stackit.cloud
release-notes
-
vulncheck.com
/advisories/stackit-iaas-api-privilege-escalation-via-service-account-attachment
third-party-advisory
Sources
- CVE List CVE-2026-39910
- NVD CVE-2026-39910
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.