CVE-2026-99236 is a high-severity vulnerability in the Linux kernel's tracing subsystem. It involves improper handling of incomplete event filter expressions, where trailing logical operators in filter predicates are not correctly rejected. This flaw can lead to out-of-bounds memory reads during filter parsing, potentially allowing an attacker with limited privileges to cause information disclosure or system instability. The issue is triggered via the PERF_EVENT_IOC_SET_FILTER interface. The vulnerability has been addressed by rejecting incomplete expressions that leave unresolved logical operators, preventing unsafe memory access.