CVE-2021-26340

A malicious hypervisor in conjunction with an unprivileged attacker process inside an SEV/SEV-ES...

8.4 High

A malicious hypervisor in conjunction with an unprivileged attacker process inside an SEV/SEV-ES guest VM may fail to flush the Translation Lookaside Buffer (TLB) resulting in unexpected behavior inside the virtual machine (VM).

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: None

Exploit likelihood

0.25%Down 0.2 points since Dec 11, 2021

What each source reports

NVD Score used 8.4

Record: CVE-2021-26340
CVSS 3.1: 8.4 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
CVSS 2.0: 3.6 LowAV:L/AC:L/Au:N/C:P/I:P/A:N
Updated: 2026-11-02

CVE List No score

Record: CVE-2021-26340
Updated: 2026-11-02

EUVDEUVD-2021-13146 No score

Record: EUVD-2021-13146
Updated: 2026-11-03

GitHub AdvisoriesGHSA-8qrv-qg3h-g8m6 No score

A malicious hypervisor in conjunction with an unprivileged attacker process inside an SEV/SEV-ES...

Record: GHSA-8qrv-qg3h-g8m6
Updated: 2026-11-02

Affected products

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History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-26340 is a high vulnerability (CVSS 8.4) in Amd Epyc™, published December 10, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. No source names a fixed version.