CVE-2026-100839
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.
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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.
CVSS
- Versión: 4.0
- Vector: 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
- Puntuación base: 8.4
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.15%
- Percentil entre todas las CVEs puntuadas: 4
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto principal
T1059Command and Scripting Interpreterexecution90 % - Impacto secundario
T1005Data from Local Systemcollection85 % - Impacto secundario
T1565.001Stored Data Manipulationimpact80 %
Inyección AML en tablas ACPI permite ejecución de código con privilegios del kernel (T1059) y acceso a memoria privada de la VM (T1005) o modificación de datos (T1565.001). Requiere control del host (AV:L/PR:L) para explotar la ausencia de validación (CWE-94).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-94
Referencias
JSON original (NVD)
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"published": "2026-09-27T02:17:22.230",
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"descriptions": [
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"value": "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."
}
],
"lastModified": "2026-09-30T16:17:02.070",
"sourceIdentifier": "disclosure@vulncheck.com"
}