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01 Record

CVE-2021-26379

Insufficient input validation of mailbox data in the SMU may allow an attacker to coerce the SMU to corrupt SMRAM, potentially leading to a loss of integrity and privilege escalation.

CriticalPUBLISHEDCNA: AMD
CNA base score9.8 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

02 Description

Insufficient input validation of mailbox data in the SMU may allow an attacker to coerce the SMU to corrupt SMRAM, potentially leading to a loss of integrity and privilege escalation.

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.68% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 52.0% of scored records. A rank, not a probability.
NVD base score
9.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2023-05-09 18:36Z3 YR AGO
Last updated
2025-01-28 16:02Z1 YR AGO
Reserved
2021-01-29
Assigning CNA
AMD
Record state
PUBLISHED
Severity
Critical (CVSS 9.8)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
No CWE assigned
Data version
5.1
Document digest
ae6946768eff1c7acad8fa5c92e6bb94a80c65ed12c35033857e22ba2aff0391

05 Affected products

VendorProductVersionsPlatforms
AMD2nd Gen AMD EPYC™variousx86
AMD3rd Gen AMD EPYC™variousx86

06 References