CVE-2026-53236

tcp: restrict SO_ATTACH_FILTER to priv users

Published: 6/25/2026 Last updated: 6/25/2026 Reserved: 6/9/2026

In the Linux kernel, the following vulnerability has been resolved: tcp: restrict SO_ATTACH_FILTER to priv users This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability. This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers.

CNA assigner: Linux (416baaa9-dc9f-4396-8d5f-8c081fb06d67) Requested by: n/a

Opam packages affected (29)

albatross cdrom conf-bpftool conf-libbpf conf-linux-libc-dev core core_unix hvsock mirage-block-unix mm ocaml-probes ortools_solvers orun rawlink rawlink-eio rawlink-lwt restricted shell solo5 solo5-bindings-hvt solo5-bindings-spt solo5-cross-aarch64 solo5-kernel-ukvm tracy-client tuntap uring vhd-format vhd-format-lwt xapi-stdext-unix

Products affected (2)

Product	Vendor	Version
Linux	Linux	10 Version 1809 for 32-bit Systems
Linux	Linux	unspecified

CVE-2026-53236

tcp: restrict SO_ATTACH_FILTER to priv users

Opam packages affected (29)

Products affected (2)

References (6)