{"id":"CVE-2026-100839","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-100839","generatedAt":"2026-10-28T01:48:04.420Z","title":"In versions before 1.18.0, the guest kernel's ACPI/AML handling is vulnerable to an AML injection attack (\"BadAML\").","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.","published":"2026-09-27T02:17:22.000Z","lastModified":"2026-10-08T16:17:00.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":8.4,"severity":"HIGH","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/M"},"cwe":["CWE-94"],"affected":[],"epss":{"score":0.00149,"percentile":0.04017,"date":"2026-10-26","history":[{"date":"2026-09-27","score":0.00149,"percentile":0.03424}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-27T02:17:22.000Z","detail":{"score":"8.4","severity":"HIGH","publishedAt":"2026-09-27T02:17:22.230Z"},"summary":"New CVE, high severity (CVSS 8.4)."}],"references":[{"url":"https://github.com/edgelesssys/contrast/security/advisories/GHSA-g9ww-x58f-9g6m","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/contrast-before-1.18.0-aml-injection-remote-code-execution","source":"disclosure@vulncheck.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-100839","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}