CVE-2026-100839 (GCVE-0-2026-100839)

Vulnerability from cvelistv5 – Published: 2026-09-27 01:28 – Updated: 2026-10-08 15:22
VLAI
Title
Contrast before 1.18.0 AML Injection Remote Code Execution
Summary
Contrast is a confidential-computing runtime for Kubernetes. In versions before 1.18.0, the guest kernel's ACPI/AML handling is vulnerable to an AML injection attack ("BadAML"). ACPI tables containing AML bytecode are passed from the untrusted host (QEMU) to the guest firmware (OVMF) and on to the Linux kernel, whose AML interpreter executes them. An attacker controlling the host — an assumed adversary in Contrast's threat model — can craft a table with malicious, Turing-complete AML bytecode that the guest kernel interprets with access to the full guest memory, including private pages, resulting in arbitrary code execution and disclosure or modification of confidential guest data. The issue affects the AMD SEV-SNP platforms Metal-QEMU-SNP and Metal-QEMU-SNP-GPU; Metal-QEMU-TDX is not affected because ACPI table contents are measured into RTMR 0 by OVMF on Intel TDX. Version v1.18.0 mitigates the attack by sandboxing the kernel AML interpreter so that it cannot read or write private memory pages. This weakness is not specific to Contrast but is generic to Confidential Computing setups that expose the ACPI interface to the host.
Severity
8.4 (High)
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
8.4 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-30 15:16 UTC
CWE
  • CWE-94 - Improper Control of Generation of Code ('Code Injection')
Assigner
VulnCheck CNA under the mitre root
CNA scorecard B 84/100 over 8186 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
edgelesssys contrast Affected: 0 , < 1.18.0 (semver)
Unaffected: 1.18.0 (semver)
guessed Create a notification for this product.
Date Public
2026-03-24 00:00
Credits
katexochen sespiros
Show details on NVD website
To clipboard 

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