CVE-2026-53266

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: bridge: make ebt_snat ARP rewrite writable

The ebtables SNAT target keeps the Ethernet source address rewrite

behind skb_ensure_writable(skb, 0). This is intentional: at the bridge

ebtables hooks the Ethernet header is addressed through

skb_mac_header()/eth_hdr(), while skb->data points at the Ethernet

payload. Asking skb_ensure_writable() for ETH_HLEN bytes would check

the payload, not the Ethernet header, and would reintroduce the small

packet regression fixed by commit 63137bc5882a.

However, the optional ARP sender hardware address rewrite is different.

It writes through skb_store_bits() at an offset relative to skb->data:

skb_store_bits(skb, sizeof(struct arphdr), info->mac, ETH_ALEN)

skb_header_pointer() only safely reads the ARP header; it does not make

the later sender hardware address range writable. If that range is

still held in a nonlinear skb fragment backed by a splice-imported f

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References