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Fencer Intel
medium 5.5

CVE-2021-26355 json

Insufficient fencing and checks in System Management Unit (SMU) may result in access to invalid message port registers that could result in…

published 3y ago modified 4mo ago also EUVD-2021-13161

cvss
5.5
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 7%
public exploits
0
none known

Summary

Insufficient fencing and checks in System Management Unit (SMU) may result in access to invalid message port registers that could result in a potential denial-of-service.

Patch / fix

  • amd epyc_7003_firmware milanpi-sp3_1.0.0.7
  • amd epyc_72f3_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7313_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7313p_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7343_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7373x_firmware milanpi-sp3_1.0.0.7
  • amd epyc_73f3_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7413_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7443_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7443p_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7453_firmware milanpi-sp3_1.0.0.7
  • amd epyc_74f3_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7513_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7543_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7543p_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7573x_firmware milanpi-sp3_1.0.0.7
  • amd epyc_75f3_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7643_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7663_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7713_firmware milanpi-sp3_1.0.0.7

Is CVE-2021-26355 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • AMD 3rd Gen EPYC

Classification

Weakness
  • CWE-693 Protection Mechanism Failure

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.