CVE-2021-26339

Name: CVE-2021-26339
Creator: NVD / NIST
Published: 2022-05-11T17:15:08.253+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.26%

Last modified Jun 17, 2026

CVE-2021-26339 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. 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.. EPSS estimates a 0.26% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.26%

17.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
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
Amd	Epyc 7473x Firmware	< milanpi-sp3_1.0.0.7
Amd	Epyc 7573x Firmware	< milanpi-sp3_1.0.0.7
Amd	Epyc 7373x Firmware	< milanpi-sp3_1.0.0.7
Amd	Ryzen 7 5700g Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 7 5700ge Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 5 5700g Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 5 5700ge Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 3 5300g Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 3 5300ge Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 7 4700g Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 7 4700ge Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 5 4600g Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 5 4600ge Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 3 4300g Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen 3 4300ge Firmware	< comboam4_v2_pi_1.2.0.6c
Amd	Ryzen Threadripper Pro 3945wx Firmware	All versions
Amd	Ryzen Threadripper Pro 3955wx Firmware	All versions
Amd	Ryzen Threadripper Pro 3975wx Firmware	All versions
Amd	Ryzen Threadripper Pro 3995wx Firmware	All versions
Amd	Ryzen Threadripper Pro 5945wx Firmware	All versions
Amd	Ryzen Threadripper Pro 5955wx Firmware	All versions
Amd	Ryzen Threadripper Pro 5965wx Firmware	All versions
Amd	Ryzen Threadripper Pro 5975wx Firmware	All versions
Amd	Ryzen Threadripper Pro 5995wx Firmware	All versions
Amd	Ryzen 3 2200u Firmware	All versions
Amd	Ryzen 3 2300u Firmware	All versions
Amd	Ryzen 3 Pro 2300u Firmware	All versions
Amd	Ryzen 5 2500u Firmware	All versions
Amd	Ryzen 5 Pro 2500u Firmware	All versions
Amd	Ryzen 5 2600h Firmware	All versions

Showing 50 of 84 affected configurations. See NVD for the full list.

References

https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1027Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1028Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1027Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1028Vendor Advisory

Timeline

Published: May 11, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-26339?

How severe is CVE-2021-26339?

CVE-2021-26339 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.

How do I fix CVE-2021-26339?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-26339?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST