Multiple stack consumption vulnerabilities in the kernel in NetBSD 4.0, 5.0 before 5.0.3, and 5.1 before 5.1.1, when IPsec is enabled, allow remote attackers to cause a denial of service (memory corruption and panic) or possibly have unspecified other impact via a crafted (1) IPv4 or (2) IPv6 packet with nested IPComp headers.