Incorrect transport parsing via misplaced network header
Published Sep 4, 2026 · Updated Sep 4, 2026
Incorrect transport-header parsing in affected Linux kernels allows attackers to trigger unspecified impact via VLAN-tagged TAP frames. tap_get_user_xdp advances network_header before probing while skb->protocol still identifies VLAN, causing the flow dissector to treat the inner protocol header as another VLAN header and leave transport_header unset. Reaching the defect requires a VLAN-tagged frame through the TAP XDP transmit path; the Linux CVE notice states no concrete security consequence.
Summary
What happened
Incorrect transport-header parsing in affected Linux kernels allows attackers to trigger unspecified impact via VLAN-tagged TAP frames. tap_get_user_xdp advances network_header before probing while skb->protocol still identifies VLAN, causing the flow dissector to treat the inner protocol header as another VLAN header and leave transport_header unset. Reaching the defect requires a VLAN-tagged frame through the TAP XDP transmit path; the Linux CVE notice states no concrete security consequence.
The record
- CVE
- CVE-2026-80905
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 4, 2026CVE publishedPublication date reported by the CVE source.
- Sep 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=3cae5ef1f37a475faf7c40bc6a3c170779f3e0b1
- Affected versionversion=4.20.1 <4.21
- Affected versionversion=5.0
- Affected versionversion=8c76e77f9069f10505c08e02646c3ee11ad79038 <5ffaa5d7f56ab24a8e23cf131eadfef31a3bbc4b
- Affected versionversion=8c76e77f9069f10505c08e02646c3ee11ad79038 <88b79ac89ecc04d7f2613f7e1c0b46f0c4ddb2f3
- Affected versionversion=8c76e77f9069f10505c08e02646c3ee11ad79038 <cbb35cbe8db268fefe34c23df15348cf99025298
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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Your stack
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