netfilter: require Ethernet MAC header before using eth_hdr()

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: require Ethernet MAC header before using eth_hdr() `ip6t_eui64`, `xt_mac`, the `bitmap:ip,mac`, `hash:ip,mac`, and `hash:mac` ipset types, and `nf_log_syslog` access `eth_hdr(skb)` after either assuming that the skb is associated with an Ethernet device or checking only that the `ETH_HLEN` bytes at `skb_mac_header(skb)` lie between `skb->head` and `skb->data`. Make these paths first verify that the skb is associated with an Ethernet device, that the MAC header was set, and that it spans at least a full Ethernet header before accessing `eth_hdr(skb)`.

Timeline

1. Jun 25, 2026, 8:38 AM UTCCVE published
2. Oct 16, 2026, 3:25 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Oct 19, 2026, 7:57 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 4435888e1bf139d2bfe5911643d4217382136743; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 063f43361e884acd7300790e90194430275d0d0c; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 726abf97566867f808fec9d8a408eb9698bd570a; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 367abcacc13a8e2e7624408b7f593bd1e60e49d9; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 5d634afb8b83b49de562792fd0d047416a43bd4d; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in cea435ea7e868ea6fdf039bc4f2090c1d829b556; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 62443dc21114c0bbc476fa62973db89743f2f137

• Linux Linux

  2.6.12

• KernelLinux

  From 2.6.12 · fixed in 5.15.210; From 5.16.0 · fixed in 6.1.176; From 6.2.0 · fixed in 6.6.143; From 6.7.0 · fixed in 6.12.94; From 6.13.0 · fixed in 6.18.36; From 6.19.0 · fixed in 7.0.13

References 7