Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-06-03T00:00:00 kernel: inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CWE-1287

In the Linux kernel, the following vulnerability has been resolved: inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP Yizhou Zhao reported that simply having one RAW socket on protocol IPPROTO_RAW (255) was dangerous. socket(AF_INET, SOCK_RAW, 255); A malicious incoming ICMP packet can set the protocol field to 255 and match this socket, leading to FNHE cache changes. inner = IP(src="192.168.2.1", dst="8.8.8.8", proto=255)/Raw("TEST") pkt = IP(src="192.168.1.1", dst="192.168.2.1")/ICMP(type=3, code=4, nexthopmtu=576)/inner "man 7 raw" states: A protocol of IPPROTO_RAW implies enabled IP_HDRINCL and is able to send any IP protocol that is specified in the passed header. Receiving of all IP protocols via IPPROTO_RAW is not possible using raw sockets. Make sure we drop these malicious packets.

A flaw was found in the Linux kernel's handling of RAW sockets using IPPROTO_RAW. A remote attacker could send a specially crafted ICMP (Internet Control Message Protocol) packet. This malicious packet could set the protocol field to 255, causing it to be processed by a RAW socket configured for IPPROTO_RAW. This leads to unintended FNHE (Flow N-tuple Hash Entry) cache changes, which could result in unexpected network behavior.

Red Hat Enterprise Linux 10 Affected kernel Red Hat Enterprise Linux 6 Out of support scope kernel Red Hat Enterprise Linux 7 Affected kernel Red Hat Enterprise Linux 7 Affected kernel-rt Red Hat Enterprise Linux 8 Affected kernel Red Hat Enterprise Linux 8 Affected kernel-rt Red Hat Enterprise Linux 9 Affected kernel Red Hat Enterprise Linux 9 Affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-46266 https://nvd.nist.gov/vuln/detail/CVE-2026-46266 https://lore.kernel.org/linux-cve-announce/2026060337-CVE-2026-46266-1e5e@gregkh/T