CVE-2026-80906 Affecting kernel-modules-extra-common package, versions <1:6.1.186-228.374.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.17% (6th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELMODULESEXTRACOMMON-19818346
  • published15 Sept 2026
  • disclosed4 Sept 2026

Introduced: 4 Sep 2026

NewCVE-2026-80906  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-modules-extra-common to version 1:6.1.186-228.374.amzn2023 or higher.
This issue was patched in ALAS2023-2026-2143.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-modules-extra-common package and not the kernel-modules-extra-common package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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.