How severe is CVE-2021-46756?

CVE-2021-46756 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2021-46756 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-46756?

CVE-2021-46756 primarily affects Amd Epyc 72f3 Firmware. In total, 63 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-46756?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-46756 published?

CVE-2021-46756 was published on 2023-05-09 and last updated on 2026-06-17.

CVE-2021-46756

CVE-2021-46756 is a critical-severity vulnerability in Amd Epyc 72f3 Firmware with a CVSS 3.x base score of 9.1. 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-20.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Amd Epyc 72f3 Firmware
Published: 2023-05-09
Last modified: 2026-06-17

Description

Insufficient validation of inputs in SVC_MAP_USER_STACK in the ASP (AMD Secure Processor) bootloader may allow an attacker with a malicious Uapp or ABL to send malformed or invalid syscall to the bootloader resulting in a potential denial of service and loss of integrity.

Frequently asked questions

What is CVE-2021-46756?: Insufficient validation of inputs in SVC_MAP_USER_STACK in the ASP (AMD Secure Processor) bootloader may allow an attacker with a malicious Uapp or ABL to send malformed or invalid syscall to the bootloader resulting in a potential denial of service and loss of integrity.
How severe is CVE-2021-46756?: CVE-2021-46756 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2021-46756 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-46756?: CVE-2021-46756 primarily affects Amd Epyc 72f3 Firmware. In total, 63 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-46756?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-46756 published?: CVE-2021-46756 was published on 2023-05-09 and last updated on 2026-06-17.

References

Affected products (63)

cpe:2.3:o:amd:epyc_72f3_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7313_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7313p_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7343_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7373x_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_73f3_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7413_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7443_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7443p_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7453_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7473x_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_74f3_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7513_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7543_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7543p_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7573x_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_75f3_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7643_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7663_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713p_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7763_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7773x_firmware:milanpi_1.0.0.9:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7232p_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7252_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7262_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7272_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7282_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302p_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7352_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402p_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7452_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502p_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7532_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7542_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7552_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7642_firmware:romepi_1.0.0.e:*:*:*:*:*:*:*

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