Is CVE-2021-26356 in the CISA KEV catalog?

No. CVE-2021-26356 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-26356?

CVE-2021-26356 has a CVSS v3 base score of 7.4 (HIGH).

What is the EPSS score for CVE-2021-26356?

CVE-2021-26356 has an EPSS score of 0.40% (32th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-26356?

Upgrade epyc 7001 firmware to naplespi_1.0.0.h or later. Fixes are available for 72 affected products.

CVE & CISA-KEV Catalog

CVE-2021-26356

HIGH

7.4

CVSS v3

NVD

Description

A TOCTOU in ASP bootloader may allow an attacker to tamper with the SPI ROM following data read to memory potentially resulting in S3 data corruption and information disclosure.

CWE-367TOCTOU Race Condition

How to fix

Remediation Available

epyc 7001 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7002 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7232p firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7251 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7252 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7261 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7262 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7272 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7281 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7282 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 72f3 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7301 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7302 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7302p firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7313 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7313p firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7343 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7351 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7351p firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7352 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7371 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7373x firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7401 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7401p firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7402 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7402p firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7413 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7443 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7443p firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7451 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7452 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7453 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7473x firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 74f3 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7501 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7502 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7513 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7532 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7542 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7543 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7543p firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7551 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7551p firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7552 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7573x firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 75f3 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7601 firmwareNVD

Affected:< naplespi_1.0.0.hFixed in:naplespi_1.0.0.hCVE-2021-26356derived from NVD

epyc 7642 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7643 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7662 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7663 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7702 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7702p firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7713 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7713p firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7742 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7763 firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7773x firmwareNVD

Affected:< milanpi_1.0.0.6Fixed in:milanpi_1.0.0.6CVE-2021-26356derived from NVD

epyc 7f32 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7f52 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7f72 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

epyc 7h12 firmwareNVD

Affected:< romepi_1.0.0.dFixed in:romepi_1.0.0.dCVE-2021-26356derived from NVD

ryzen 5 5500 firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 5 5600 firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 5 5600x firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 7 5700x firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 7 5800 firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 7 5800x3d firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 7 5800x firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 9 5900 firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 9 5900x firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

ryzen 9 5950x firmwareNVD

Affected:< comboam4_v2_pi_1.2.0.6Fixed in:comboam4_v2_pi_1.2.0.6CVE-2021-26356derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

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

Exploit Intelligence

0.40%probability of exploitation in 30 days

32ndpercentile

Low risk: more likely to be exploited than 32% of all known CVEs.

References

Vendor Advisory2

Related Vulnerabilities

Other CWE-367 (TOCTOU Race Condition) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2022-36980	High	8.1	83%	-	Fix
CVE-2024-30088	High	7.0	68%	KEV + Ransom	Fix
CVE-2004-0594	Medium	5.1	55%	-	Fix
CVE-2024-50379	Critical	9.8	44%	-	Fix
CVE-2023-38146	High	8.8	39%	-	Fix
CVE-2024-0132	Critical	9.0	37%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-01-28.