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Fencer Vulns
medium 5.5

CVE-2021-26339 json

A bug in AMD CPU’s core logic may allow for an attacker, using specific code from an unprivileged VM, to trigger a CPU core hang resulting…

published 2022-05-11 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-13145

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits
0
none known

Summary

A bug in AMD CPU’s core logic may allow for an attacker, using specific code from an unprivileged VM, to trigger a CPU core hang resulting in a potential denial of service. AMD believes the specific code includes a specific x86 instruction sequence that would not be generated by compilers.

Patch / fix

  • amd epyc_7763_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7713p_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7713_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7663_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7643_firmware milanpi-sp3_1.0.0.7
  • amd epyc_75f3_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7543p_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7543_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7513_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_7443p_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7443_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7413_firmware milanpi-sp3_1.0.0.7
  • amd epyc_73f3_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7343_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7313p_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7313_firmware milanpi-sp3_1.0.0.7
  • amd epyc_72f3_firmware milanpi-sp3_1.0.0.7
  • amd epyc_7773x_firmware milanpi-sp3_1.0.0.7
  • kernel-firmware SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 20220509-150400.4.5.1
  • kernel-firmware SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 20191118-150000.3.42.1
  • kernel-firmware SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +3 more 20190618-5.25.2
  • kernel-firmware SLE Module for Basesystem 15 SP3, SLE Micro 5.2, SLE Micro 5.1 +1 more 20210208-150300.4.10.1
  • kernel-firmware SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES 15 SP2-LTSS +12 more 20200107-150100.3.31.1

suse advisories SUSE-SU-2022:1923-1SUSE-SU-2022:1847-1SUSE-SU-2022:1846-1SUSE-SU-2022:1840-1SUSE-SU-2022:1751-1

  • kernel-firmware-all openSUSE Tumbleweed 20250206-1.1
  • kernel-firmware-amdgpu openSUSE Tumbleweed 20250206-1.1
  • kernel-firmware-ath10k openSUSE Tumbleweed 20250206-1.1
  • kernel-firmware-ath11k openSUSE Tumbleweed 20250206-1.1
  • kernel-firmware-ath12k openSUSE Tumbleweed 20250206-1.1
  • kernel-firmware-atheros openSUSE Tumbleweed 20250206-1.1
  • kernel-firmware-bluetooth openSUSE Tumbleweed 20250208-1.1
  • kernel-firmware-bnx2 openSUSE Tumbleweed 20250206-1.1

opensuse advisories openSUSE-SU-2025:14804-1openSUSE-SU-2025:14769-1openSUSE-SU-2025:14770-1openSUSE-SU-2025:14771-1openSUSE-SU-2025:14772-1openSUSE-SU-2025:14773-1

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.9 AV:L/AC:L/Au:N/C:N/I:N/A:C

Affected products

  • AMD EPYC™ Processors
  • AMD Ryzen™ Series
  • AMD Athlon™ Series

References

Sources

Fencer Vulns 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.