How severe is CVE-2021-26336?

CVE-2021-26336 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-26336 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26336?

CVE-2021-26336 primarily affects Amd Epyc 7003 Firmware. In total, 95 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26336?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-26336 published?

CVE-2021-26336 was published on 2021-11-16 and last updated on 2026-06-17.

CVE-2021-26336

CVE-2021-26336 is a medium-severity vulnerability in Amd Epyc 7003 Firmware with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 4.9
EPSS exploit prediction: 0% (12th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Amd Epyc 7003 Firmware
Published: 2021-11-16
Last modified: 2026-06-17

Description

Insufficient bounds checking in System Management Unit (SMU) may cause invalid memory accesses/updates that could result in SMU hang and subsequent failure to service any further requests from other components.

Frequently asked questions

What is CVE-2021-26336?: Insufficient bounds checking in System Management Unit (SMU) may cause invalid memory accesses/updates that could result in SMU hang and subsequent failure to service any further requests from other components.
How severe is CVE-2021-26336?: CVE-2021-26336 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-26336 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26336?: CVE-2021-26336 primarily affects Amd Epyc 7003 Firmware. In total, 95 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26336?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-26336 published?: CVE-2021-26336 was published on 2021-11-16 and last updated on 2026-06-17.

References

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

Affected products (95)

cpe:2.3:o:amd:epyc_7003_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7002_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_72f3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7313_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7313p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7343_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_73f3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7413_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7443_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7443p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7453_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_74f3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7513_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7543_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7543p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_75f3_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7643_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7663_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7763_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7232p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7252_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7262_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7272_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7282_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7352_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7452_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502p_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7532_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7542_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7552_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7642_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7662_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7702_firmware:*:*:*:*:*:*:*:*

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