---
id: "CVE-2026-28247"
page: "https://infrastack.ai/live/CVE-2026-28247"
kind: "vulnerability"
aliases: ["CVE-2026-28247"]
title: "AMD SEV firmware: a hypervisor can alter guest page encryption bits"
severity: "medium"
cvss: 5.9
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["amd", "hypervisor", "infrastructure", "sev", "virtualization"]
not_affected_if: ["no-sev-guests"]
published_at: "2026-11-10T22:18:32+00:00"
first_seen_at: "2026-11-10T22:27:30+00:00"
updated_at: "2026-11-10T22:29:20+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-28247", "first_seen_at": "2026-11-10T22:27:30+00:00"}]
exploit_sources: []
---

# AMD SEV firmware: a hypervisor can alter guest page encryption bits

Link for people: https://infrastack.ai/live/CVE-2026-28247 (this .md is for agents)

AMD Secure Encrypted Virtualization firmware has an access control flaw in mirrored or aliased memory regions. A malicious hypervisor can change the encryption bit on guest context pages, which can lead to loss of guest data integrity.

_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-2026-28247

## From the sources

Improper Access Control Applied to Mirrored or Aliased Memory Regions in AMD Secure Encrypted Virtualization (SEV) firmware could allow a malicious hypervisor to change the encryption bit for guest context pages potentially resulting in loss of integrity.

---

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