How severe is CVE-2021-26387?

CVE-2021-26387 has a CVSS 3.x base score of 3.9, rated low severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2021-26387 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-26387?

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

Does CVE-2021-26387 have an EU (EUVD) identifier?

Yes. CVE-2021-26387 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-13193.

When was CVE-2021-26387 published?

CVE-2021-26387 was published on 2024-08-13 and last updated on 2026-06-17.

CVE-2021-26387

CVE-2021-26387 is a low-severity vulnerability with a CVSS 3.x base score of 3.9. 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-863.

Key facts

Severity: Low (CVSS 3.x base score 3.9)
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-13193
Weakness: CWE-863
Published: 2024-08-13
Last modified: 2026-06-17

Description

Insufficient access controls in ASP kernel may allow a privileged attacker with access to AMD signing keys and the BIOS menu or UEFI shell to map DRAM regions in protected areas, potentially leading to a loss of platform integrity.

Frequently asked questions

What is CVE-2021-26387?: Insufficient access controls in ASP kernel may allow a privileged attacker with access to AMD signing keys and the BIOS menu or UEFI shell to map DRAM regions in protected areas, potentially leading to a loss of platform integrity.
How severe is CVE-2021-26387?: CVE-2021-26387 has a CVSS 3.x base score of 3.9, rated low severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2021-26387 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-26387?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-26387 have an EU (EUVD) identifier?: Yes. CVE-2021-26387 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-13193.
When was CVE-2021-26387 published?: CVE-2021-26387 was published on 2024-08-13 and last updated on 2026-06-17.

References

Other CWE-863 (Incorrect Authorization) vulnerabilities

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CVE-2026-46595 — Critical (CVSS 10.0): Previously, CVE-2024-45337 fixed an authorization bypass for misused ssh server configurations; if any other type of…
CVE-2026-33105 — Critical (CVSS 10.0): Improper authorization in Microsoft Azure Kubernetes Service allows an unauthorized attacker to elevate privileges over…
CVE-2026-32213 — Critical (CVSS 10.0): Improper authorization in Azure AI Foundry allows an unauthorized attacker to elevate privileges over a network.

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