SB20260626117 - NULL pointer dereference in Linux kernel netfilter

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-53220)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a NULL pointer dereference in ebt_redirect_tg() in net/bridge/netfilter/ebt_redirect.c when reinjecting an NFQUEUE packet after bridge port state changes. A local user can remove or reassign the bridge port before reinjection to cause a denial of service.

The issue occurs if the bridge port is removed between the original hook invocation and NFQUEUE reinjection, and the device may also be moved to a different virtual device such as macvlan.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/43330a1e8aace6b5a8de9aba127e9e394ab49b0f
• https://git.kernel.org/stable/c/4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0
• https://git.kernel.org/stable/c/ccb9fd4b87538ccf19ccff78ee26700526d94867
• https://git.kernel.org/stable/c/d4b1301fd3c9e5e105fd3767c68bc4ba558bb228