Anthropic security research reportedly found CVE-2026-98432, a network-reachable use-after-free flaw in the Linux kernel's IPv4 TCP handshake handling. The report says an unpublished internal Claude model discovered the issue and generated a two-stage exploit that bypassed kernel address randomization and executed commands with Root privileges, although the exploit code was not released. Upstream fixes are available, but the cited report says several Ubuntu releases remained affected as of November 1.