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.
Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sun, 27 Sep 2026 12:15:00 +0000
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| Description | 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. | |
| Title | Contrast before 1.18.0 AML Injection Remote Code Execution | |
| Weaknesses | CWE-94 | |
| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-09-27T01:28:36.154Z
Reserved: 2026-09-26T23:23:03.411Z
Link: CVE-2026-100839
No data.
Status : Received
Published: 2026-09-27T02:17:22.230
Modified: 2026-09-27T02:17:22.230
Link: CVE-2026-100839
No data.
OpenCVE Enrichment
Updated: 2026-09-27T11:42:52Z
Weaknesses