CVE-2026-46266

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < db76b75ede3810e7cf9cfea5067d4f3e0993768baffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 19e42490c89bac9a388f28179e66bebbef350f99affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 531c1aec81bfe19d00af13da5531fbb8209e4bd2affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 719d3932b8f6e3348ce2f0ac58e278301fc17575affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c89477ad79446867394360b29bb801010fc3ff22affected
LinuxLinux2.6.12affected
LinuxLinux0 < 2.6.12unaffected
LinuxLinux6.6.128 <= 6.6.*unaffected
LinuxLinux6.12.75 <= 6.12.*unaffected
LinuxLinux6.18.14 <= 6.18.*unaffected
LinuxLinux6.19.4 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References