How severe is CVE-2020-5956?

CVE-2020-5956 has a CVSS 3.x base score of 7.5, rated high 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 none.

Is CVE-2020-5956 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5956?

CVE-2020-5956 affects Insyde Insydeh2o. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-5956?

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

When was CVE-2020-5956 published?

CVE-2020-5956 was published on 2022-01-05 and last updated on 2026-06-17.

CVE-2020-5956

CVE-2020-5956 is a high-severity vulnerability in Insyde Insydeh2o with a CVSS 3.x base score of 7.5. 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Insyde Insydeh2o
Published: 2022-01-05
Last modified: 2026-06-17

Description

An issue was discovered in SdLegacySmm in Insyde InsydeH2O with kernel 5.1 before 05.15.11, 5.2 before 05.25.11, 5.3 before 05.34.11, and 5.4 before 05.42.11. The software SMI handler allows untrusted external input because it does not verify CommBuffer.

Frequently asked questions

What is CVE-2020-5956?: An issue was discovered in SdLegacySmm in Insyde InsydeH2O with kernel 5.1 before 05.15.11, 5.2 before 05.25.11, 5.3 before 05.34.11, and 5.4 before 05.42.11. The software SMI handler allows untrusted external input because it does not verify CommBuffer.
How severe is CVE-2020-5956?: CVE-2020-5956 has a CVSS 3.x base score of 7.5, rated high 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 none.
Is CVE-2020-5956 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5956?: CVE-2020-5956 affects Insyde Insydeh2o. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-5956?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-5956 published?: CVE-2020-5956 was published on 2022-01-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:insyde:insydeh2o:*:*:*:*:*:*:*:*

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