CVE-2026-89443: Linux

High severity, CVSS 7.1. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: platform/x86: ISST: Validate level in perf mask ioctls isst_if_get_perf_level_mask() and isst_if_get_base_freq_mask() use the user-provided level as an index into perf_levels[] via _read_pp_level_info() and _read_bf_level_info(), but neither helper validates it first. The adjacent level-info helpers reject levels above max_level before reading the same per-level register block. Add the same bounds checks to the mask helpers, and reject disabled SST-PP levels in isst_if_get_perf_level_mask() to match isst_if_get_perf_level_info(). This prevents out-of-bounds reads from the per-level offset table on invalid ioctl input.

Affected products

• Linux Linux: from 6.4, before 6.6.157 (fixed in 6.6.157); from 6.7, before 6.12.109 (fixed in 6.12.109); from 6.13, before 6.18.50 (fixed in 6.18.50); from 6.19, before 7.2.4 (fixed in 7.2.4)

Published 2026-09-11. Last modified 2026-09-14.