Bug 2492747 (CVE-2026-53131)

Summary: CVE-2026-53131 kernel: netfilter: require Ethernet MAC header before using eth_hdr()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's netfilter component. Certain netfilter modules, including `ip6t_eui64` and `xt_mac`, accessed Ethernet MAC header data without first verifying that an Ethernet device was associated with the network packet or that the MAC header was present and of sufficient length. This oversight could allow a local or remote attacker to trigger an out-of-bounds read, potentially leading to a system crash and a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-06-25 10:03:37 UTC 
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)`.
Comment 1 Keith Grant 2026-06-25 22:49:47 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062539-CVE-2026-53131-0b14@gregkh/T