CVE-2026-80906

CVE CVE-2026-80906EUVD EUVD-2026-71665Published 2026-09-04T17:19:16.000Z

What the advisory describes

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_header() never calls skb_set_transport_header(), leaving transport_header at its uninitialized sentinel value (~0U). Move skb_probe_transport_header() to before skb_set_network_header(). At the time skb_probe_transport_header() is called, network_header still points to the VLAN header, so nhoff correctly points to the VLAN header. The flow dissector can then parse the VLAN header, extract the inner EtherType, and advance nhoff to the inner protocol header, allowing transport_header to be set correctly.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux 9ff46c36df2e0a1ac352f2f4038eaf3f0f7361b8 <fa86bc52ea8ba981f74f851fd61e2a3d3bc0feac; dfed913e8b55a0c2c4906f1242fd38fd9a116e49 <6386a6ffa2efba2965ed8e4fa303582c0b76a215; patch: 0; patch: 7.1.10; 5.4.229 <5.5; patch: 6.18.46; patch: 6.12.105; patch: 5.15.217; dfed913e8b55a0c2c4906f1242fd38fd9a116e49 <5479eb9b355f44745d7ccfe112386bd4f96eceea; patch: 5.10.266; dfed913e8b55a0c2c4906f1242fd38fd9a116e49 <6971cf319263d6a1b4096f9248aca9e57d77a1eb; patch: 6.6.153; dfed913e8b55a0c2c4906f1242fd38fd9a116e49 <e451e20adb869a983a21dda158625f024142e61f; 5.19; patch: 6.1.184; patch: 7.2; dfed913e8b55a0c2c4906f1242fd38fd9a116e49 <01fdecc0480d916c799dbee584833a4a37e94d06; ad3f90a9c4a2c74bb3711f2031bffda4ec44c849; 5.15.87 <5.15.217; 5.10.163 <5.10.266; c2137d565ceb505de69593c181a0543bc4083838 <a4b82de96d465ddb44bc931145c0fa80c4fe9c9c; dfed913e8b55a0c2c4906f1242fd38fd9a116e49 <f9297abbcaba760b7a7b9d63b839f607f738013e

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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