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Fencer Intel
high 7.1

CVE-2021-26402 json

Insufficient bounds checking in ASP (AMD Secure Processor) firmware while handling BIOS mailbox commands, may allow an attacker to write pa…

published 3y ago modified 4mo ago also EUVD-2021-13208

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

Summary

Insufficient bounds checking in ASP (AMD Secure Processor) firmware while handling BIOS mailbox commands, may allow an attacker to write partially-controlled data out-of-bounds to SMM or SEV-ES regions which may lead to a potential loss of integrity and availability.

Patch / fix

  • amd epyc_7h12_firmware romepi_1.0.0.c
  • amd epyc_7f72_firmware romepi_1.0.0.c
  • amd epyc_7f52_firmware romepi_1.0.0.c
  • amd epyc_7f32_firmware romepi_1.0.0.c
  • amd epyc_7742_firmware romepi_1.0.0.c
  • amd epyc_7702p_firmware romepi_1.0.0.c
  • amd epyc_7702_firmware romepi_1.0.0.c
  • amd epyc_7662_firmware romepi_1.0.0.c
  • amd epyc_7642_firmware romepi_1.0.0.c
  • amd epyc_7552_firmware romepi_1.0.0.c
  • amd epyc_7542_firmware romepi_1.0.0.c
  • amd epyc_7532_firmware romepi_1.0.0.c
  • amd epyc_7502p_firmware romepi_1.0.0.c
  • amd epyc_7502_firmware romepi_1.0.0.c
  • amd epyc_7452_firmware romepi_1.0.0.c
  • amd epyc_7402_firmware romepi_1.0.0.c
  • amd epyc_7402p_firmware romepi_1.0.0.c
  • amd epyc_7352_firmware romepi_1.0.0.c
  • amd epyc_7302p_firmware romepi_1.0.0.c
  • amd epyc_7302_firmware romepi_1.0.0.c

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
NVD 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
CNA 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Affected products

  • AMD 2nd Gen EPYC
  • AMD 3rd Gen EPYC

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.