CVE-2026-64028: Linux

EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: tracing: Avoid NULL return from hist_field_name() on truncation hist_field_name() returns "" everywhere except the fully-qualified VAR_REF/EXPR case, where snprintf() truncation returns NULL early and bypasses the bottom NULL->"" guard. Callers don't expect NULL: strcat(expr, hist_field_name(field, 0)) at trace_events_hist.c:1758 and the strcmp() in the sort-key match loop at :4804 both deref it. system and event_name are bounded by MAX_EVENT_NAME_LEN, but the field name on a VAR_REF is kstrdup'd from a histogram variable name parsed out of the trigger string and has no length cap, so a long enough var name in a fully qualified reference can reach the truncation path. Keep the length check but leave field_name as "" on overflow.

Affected products

• Linux Linux: from 6.6.141, before 6.6.142 (fixed in 6.6.142); from 6.12.91, before 6.12.92 (fixed in 6.12.92); from 6.18.33, before 6.18.34 (fixed in 6.18.34); from 7.0.10, before 7.0.11 (fixed in 7.0.11)

Published 2026-07-19. Last modified 2026-07-30.