CVE-2026-80906

/// Technical description

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

net: packet: fix wrong transport_header when sending VLAN-tagged frame

In packet_parse_headers(), when processing a VLAN-tagged frame,

skb_set_network_header() is called to advance network_header past the

VLAN tag to the inner protocol header. skb_probe_transport_header() is

then called with skb->protocol still set to the outer VLAN EtherType

(e.g. ETH_P_8021Q), while nhoff (derived from skb_network_offset())

already points past the VLAN tag to the inner protocol header.

In __skb_flow_dissect(), proto is initialized to ETH_P_8021Q and nhoff

points past the VLAN tag. When the dissector hits case ETH_P_8021Q, it

reads a struct vlan_hdr at nhoff via __skb_header_pointer(), but that

offset contains the inner protocol header (e.g. an IP header). The bytes

are misinterpreted as a VLAN header, yielding a garbage encapsulated

EtherType that matches no known protocol. The dissector returns false,

so skb_probe_transport_heade

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. 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.

/// References