CVE-2021-26342

In SEV guest VMs, the CPU may fail to flush the Translation Lookaside Buffer (TLB) following a particular sequence of operations that includes creation of a new virtual machine control block (VMCB). The failure to flush the TLB may cause the microcode to use stale TLB translations which may allow for disclosure of SEV guest memory contents. Users of SEV-ES/SEV-SNP guest VMs are not impacted by this vulnerability.

Published: 2022-05-11 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-26342 is rated Low Risk (18.1/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.06%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-26342

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 0.04% 0.06% +0.01%
2 2025-03-29 0.06% 0.04% -0.01%
3 2025-03-17 — 0.06% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-26342

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.3 3.1 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.8 1.4 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-26342

OS Trackers for CVE-2021-26342

vendor priority summary link
suse medium CVE-2021-26342 severity moderate: SUSE including 436 source package names (kernel-firmware, kernel-firmware-20170530-21.34.1, …), 756 product×package rows across 60 product lines (Container rancher/elemental-teal-rt/5.3, Container rancher/elemental-teal-rt/5.4, … (60 product lines)): Fixed 755, Known Not Affected 1. https://www.suse.com/security/cve/CVE-2021-26342/

Affected software / configurations for CVE-2021-26342

Vendor Product Version Raw CPE
amd epyc_7763_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7763_firmware:*:*:*:*:*:*:*:*
amd epyc_7713p_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7713p_firmware:*:*:*:*:*:*:*:*
amd epyc_7713_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7713_firmware:*:*:*:*:*:*:*:*
amd epyc_7663_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7663_firmware:*:*:*:*:*:*:*:*
amd epyc_7643_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7643_firmware:*:*:*:*:*:*:*:*
amd epyc_75f3_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_75f3_firmware:*:*:*:*:*:*:*:*
amd epyc_7543p_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7543p_firmware:*:*:*:*:*:*:*:*
amd epyc_7543_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7543_firmware:*:*:*:*:*:*:*:*
amd epyc_7513_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7513_firmware:*:*:*:*:*:*:*:*
amd epyc_7453_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7453_firmware:*:*:*:*:*:*:*:*
amd epyc_74f3_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_74f3_firmware:*:*:*:*:*:*:*:*
amd epyc_7443p_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7443p_firmware:*:*:*:*:*:*:*:*
amd epyc_7443_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7443_firmware:*:*:*:*:*:*:*:*
amd epyc_7413_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7413_firmware:*:*:*:*:*:*:*:*
amd epyc_73f3_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_73f3_firmware:*:*:*:*:*:*:*:*
amd epyc_7343_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7343_firmware:*:*:*:*:*:*:*:*
amd epyc_7313p_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7313p_firmware:*:*:*:*:*:*:*:*
amd epyc_7313_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7313_firmware:*:*:*:*:*:*:*:*
amd epyc_72f3_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_72f3_firmware:*:*:*:*:*:*:*:*
amd epyc_7773x_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7773x_firmware:*:*:*:*:*:*:*:*
amd epyc_7473x_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7473x_firmware:*:*:*:*:*:*:*:*
amd epyc_7573x_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7573x_firmware:*:*:*:*:*:*:*:*
amd epyc_7373x_firmware < milanpi-sp3_1.0.0.7 cpe:2.3:o:amd:epyc_7373x_firmware:*:*:*:*:*:*:*:*
amd epyc_7001_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7001_firmware:*:*:*:*:*:*:*:*
amd epyc_7251_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7251_firmware:*:*:*:*:*:*:*:*
amd epyc_7261_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7261_firmware:*:*:*:*:*:*:*:*
amd epyc_7281_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7281_firmware:*:*:*:*:*:*:*:*
amd epyc_7301_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7301_firmware:*:*:*:*:*:*:*:*
amd epyc_7351_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7351_firmware:*:*:*:*:*:*:*:*
amd epyc_7351p_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7351p_firmware:*:*:*:*:*:*:*:*
amd epyc_7371_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7371_firmware:*:*:*:*:*:*:*:*
amd epyc_7401_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7401_firmware:*:*:*:*:*:*:*:*
amd epyc_7401p_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7401p_firmware:*:*:*:*:*:*:*:*
amd epyc_7451_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7451_firmware:*:*:*:*:*:*:*:*
amd epyc_7501_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7501_firmware:*:*:*:*:*:*:*:*
amd epyc_7551_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7551_firmware:*:*:*:*:*:*:*:*
amd epyc_7551p_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7551p_firmware:*:*:*:*:*:*:*:*
amd epyc_7601_firmware < naplespi-sp3_1.0.0.h cpe:2.3:o:amd:epyc_7601_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-26342

cvelogic Threat Intelligence