CVE-2026-89588 and is rated High severity with a CVSS score of 8.4. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CISA KEVNot listedBased on the latest collected catalog
EPSS0.2%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-89588?
In the Linux kernel, the following vulnerability has been resolved:
ACPI: APEI: GHES: fix ARM section length accounting after header
In ghes_handle_arm_hw_error(), after skipping the cper_sec_proc_arm header with (err + 1), the remaining length was reduced by sizeof(err) (pointer size) instead of sizeof(*err) (structure size).
That overestimates the bytes left for cper_arm_err_info records and can let the parser read past the CPER section when err_info_num is large enough relative to error_data_length.
Use sizeof(*err) so the length accounting matches the pointer advance and the earlier sizeof(*err) size check.