CVE-2020-5956: Insyde INSYDEH2O

High severity, CVSS 7.5. EPSS: 0.8% chance of exploitation in the next 30 days.

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.

Affected products

• Insyde INSYDEH2O: from 5.2, before 5.25.11 (fixed in 5.25.11); from 5.1, before 05.15.11 (fixed in 05.15.11); from 5.3, before 05.34.11 (fixed in 05.34.11); from 5.4, before 05.42.11 (fixed in 05.42.11)

Published 2022-01-05. Last modified 2026-06-17.