CVE Catalog

CVE-2026-80906

Low risk· EPSS 6%
Published: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

6th percentile - higher than 6% of all known CVEs

Summary

A vulnerability in the Linux kernel's packet_parse_headers() function affects sending VLAN-tagged frames. Incorrect call order leaves transport_header uninitialized, potentially causing incorrect network stack behavior.

Risk Assessment

The organization may experience failures or unpredictable behavior in systems using VLAN packets, impacting network service integrity and availability.

Recommendation

Apply the official Linux kernel patch immediately and monitor vendor security advisories.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS