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

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_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.

Timeline

Scores

No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.

EPSS (exploitation in 30 days)

0.17% · top 94% of all CVEs (11 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.

Affected products

• Linux · Linux

  • affected c2137d565ceb505de69593c181a0543bc4083838 – < a4b82de96d465ddb44bc931145c0fa80c4fe9c9c
  • affected 9ff46c36df2e0a1ac352f2f4038eaf3f0f7361b8 – < fa86bc52ea8ba981f74f851fd61e2a3d3bc0feac
  • affected dfed913e8b55a0c2c4906f1242fd38fd9a116e49 – < 5479eb9b355f44745d7ccfe112386bd4f96eceea
  • affected dfed913e8b55a0c2c4906f1242fd38fd9a116e49 – < e451e20adb869a983a21dda158625f024142e61f
  • affected dfed913e8b55a0c2c4906f1242fd38fd9a116e49 – < 6971cf319263d6a1b4096f9248aca9e57d77a1eb
  • affected dfed913e8b55a0c2c4906f1242fd38fd9a116e49 – < f9297abbcaba760b7a7b9d63b839f607f738013e
  • affected dfed913e8b55a0c2c4906f1242fd38fd9a116e49 – < 6386a6ffa2efba2965ed8e4fa303582c0b76a215
  • affected dfed913e8b55a0c2c4906f1242fd38fd9a116e49 – < 01fdecc0480d916c799dbee584833a4a37e94d06
  • affected ad3f90a9c4a2c74bb3711f2031bffda4ec44c849
  • affected 5.10.163 – < 5.10.266
  • affected 5.15.87 – < 5.15.217
  • affected 5.4.229 – < 5.5

• Linux · Linux

  • affected 5.19
  • unaffected < 5.19
  • unaffected 5.10.266 – ≤ 5.10.*
  • unaffected 5.15.217 – ≤ 5.15.*
  • unaffected 6.1.184 – ≤ 6.1.*
  • unaffected 6.6.153 – ≤ 6.6.*
  • unaffected 6.12.105 – ≤ 6.12.*
  • unaffected 6.18.46 – ≤ 6.18.*
  • unaffected 7.1.10 – ≤ 7.1.*
  • unaffected 7.2 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-71665 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-80906](https://cveledger.app/badge/CVE-2026-80906.svg)](https://cveledger.app/cve/CVE-2026-80906)

Record last updated 6 Nov 2026, 17:05 UTC.