---
id: "CVE-2026-40669"
page: "https://infrastack.ai/live/CVE-2026-40669"
kind: "vulnerability"
aliases: ["CVE-2026-40669"]
title: "AMD SEV firmware: off-by-one lets hypervisor attacker corrupt guest memory integrity"
severity: "medium"
cvss: 4.0
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["amd", "confidential-computing", "hypervisor", "infrastructure", "sev"]
not_affected_if: ["no-sev-enabled", "non-amd-hardware"]
published_at: "2026-11-10T22:18:32+00:00"
first_seen_at: "2026-11-10T22:27:30+00:00"
updated_at: "2026-11-10T22:31:02+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40669", "first_seen_at": "2026-11-10T22:27:30+00:00"}]
exploit_sources: []
---

# AMD SEV firmware: off-by-one lets hypervisor attacker corrupt guest memory integrity

Link for people: https://infrastack.ai/live/CVE-2026-40669 (this .md is for agents)

An off-by-one error in AMD Secure Encrypted Virtualization firmware lets an attacker who already has hypervisor access corrupt the Reverse Map Table. The result is loss of guest memory integrity for virtual machines running on affected AMD hardware.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-11-10T22:27:30+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-40669

## From the sources

An off-by-one error in AMD Secure Encrypted Virtualization (SEV) firmware could allow an attacker with hypervisor access to corrupt the Reverse Map Table (RMP) table, potentially resulting in loss of guest memory integrity.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_