CVE-2021-36357: Openpowerfoundation Skiboot

Critical severity, CVSS 9.8. EPSS: 1.2% chance of exploitation in the next 30 days.

An issue was discovered in OpenPOWER 2.6 firmware. unpack_timestamp() calls le32_to_cpu() for endian conversion of a uint16_t "year" value, resulting in a type mismatch that can truncate a higher integer value to a smaller one, and bypass a timestamp check. The fix is to use the right endian conversion function.

Affected products

• Openpowerfoundation Skiboot: version 2.6 only

Published 2021-10-22. Last modified 2026-06-17.