Contrast before 1.18.0 AML Injection Remote Code Execution

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

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.

Source published

27 Sep 2026 01:28:36 UTC

Source modified

8 Oct 2026 15:22:01 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 8.4 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

CVSS 3.1 · 8.4 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

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.

Source published

Sep 27, 2026, 1:28:36 AM (timezone not stated)

Source modified

Oct 8, 2026, 3:22:01 PM (timezone not stated)

Observed here

9 Nov 2026 04:15:41 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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EUVD CVSS 4.0 · 8.4 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

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.

Source published

27 Sep 2026 02:17:22 UTC

Source modified

8 Oct 2026 16:16:59 UTC

Observed here

25 Oct 2026 04:17:26 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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CVSS 4.0 · [email protected] · Secondary · 8.4 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/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

CVSS 3.1 · [email protected] · Secondary · 8.4 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

# BadAML BadAML is an AML injection attack that exploits the ACPI interface and allows arbitrary code execution in a confidential VM. The attack was first published in 2024: - <https://blackhat.com/eu-24/briefings/schedule/#aml-injection-attacks-on-confidential-vms-42723> - <https://dl.acm.org/doi/pdf/10.1145/3719027.3765123> ## Impact An attacker with control over the host (which is assumed in the attacker model of Contrast) can execute malicious AML code to gain arbitrary code execution within the confidential guest. AML is byte code embedded in ACPI tables that are passed from the host (QEMU) to the guest firmware (OVMF), and then passed from OVMF to the Linux kernel. The Linux kernel has an interpreter that executes the AML code. An attacker can craft a table with malicious AML code and the kernel will execute it. AML is Turing-complete and the interpreter has access to the full guest memory, including private pages. See the [paper](https://dl.acm.org/doi/pdf/10.1145/3719027.3765123) for a detailed description and background of the attack. Note that this is not a vulnerability specific to Contrast, but rather a generic vulnerability in Confidential Computing setups that use the ACPI interface. ## Affected platforms This issue affects the SNP platforms supported by Contrast: `Metal-QEMU-SNP` and `Metal-QEMU-SNP-GPU`. Users on these platforms should switch to the fixed Contrast version immediately. `Metal-QEMU-TDX` isn't affected, as the content of the ACPI tables is covered by the runtime measurements (measured into RTMR 0 by OVMF) on Intel TDX. ## Patches A sandbox similar to the one proposed in the paper has been implemented in the Linux kernel used by Contrast. The sandbox denies access to private memory pages by doing a page table lookup on every read/write by the AML interpreter. This mitigates the attack completely: While an attacker can still run AML code, the code cannot read or modify private memory pages. Shared pages are readable/writable by the host hypervisor anyway.

Source published

26 Mar 2026 19:49:27 UTC

Source modified

27 Sep 2026 11:55:30 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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CVSS_V3 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Publisher rating · HIGH

Contrast BadAML injection allows arbitrary code execution in github.com/edgelesssys/contrast

Source published

2 Apr 2026 18:42:30 UTC

Source modified

27 Sep 2026 11:55:30 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.