CVE-2026-53236 PUBLISHED

tcp: restrict SO_ATTACH_FILTER to priv users

Assigner: Linux
Reserved: 09.06.2026 Published: 25.06.2026 Updated: 25.06.2026

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.

Vendor	Linux
Product	Linux
Versions	Default: unaffected affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 3747de241a66ef2c7032d2cc2b826a47c5fa0f6a (excl.) affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to ecfe9171b26ae3eed0cd8bab7a943e9e2c9e51ba (excl.) affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 82b3e7ce10c53fc12aab8904745603efc74f8c07 (excl.) affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to ede69b8f6670600e534591664584f810d7c385f9 (excl.) affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to c68517a3e18e20997808821c5559d0cba4d776c1 (excl.) affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 5d39580f68e6ddeedd15e587282207489dfb3da2 (excl.)

Vendor	Linux
Product	Linux
Versions	Default: affected Version 2.6.12 is affected unaffected from 0 to 2.6.12 (excl.) unaffected from 6.1.176 to 6.1.* (incl.) unaffected from 6.6.143 to 6.6.* (incl.) unaffected from 6.12.94 to 6.12.* (incl.) unaffected from 6.18.36 to 6.18.* (incl.) unaffected from 7.0.13 to 7.0.* (incl.) unaffected from 7.1 to * (incl.)