Vulnerability in Linux kernel (CVE-2026-80925)
Summary
Vulnerability in Linux kernel (CVE-2026-80925). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
vlan: fix skb_under_panic and races when toggling HW VLAN offload
Toggling hardware VLAN TX offload (NETIF_F_HW_VLAN_CTAG_TX or
NETIF_F_HW_VLAN_STAG_TX) on a lower device invokes vlan_transfer_features(),
which dynamically changed vlandev->hard_header_len.
This causes two issues:
- Lockless TX paths (e.g. packet_snd in af_packet.c, ip6_finish_output2)
read dev->hard_header_len without holding RTNL lock. Mutating
hard_header_len dynamically under RTNL creates a data race where upper
layers reserve insufficient headroom based on a stale hard_header_len,
resulting in skb_under_panic when vlan_dev_hard_header() is called. - In addition, vlan_transfer_features() updated hard_header_len without
updating header_ops, causing a mismatch between allocated headroom
and header creation.
Always setting dev->hard_header_len = real_dev->hard_header_len and
dev->needed_headroom = real_dev->needed_headroom + VLAN_HLEN unconditionally
ensures:
- dev->hard_header_len remains 100% static and immutable at real_dev->hard_header_len,
eliminating all dynamic runtime updates and data races on hard_header_len. - Upper layers allocating skbs via LL_RESERVED_SPACE() will always reserve
sufficient headroom for software VLAN tag insertion (real_dev->hard_header_len +
real_dev->needed_headroom + VLAN_HLEN). - vlandev inherits real_dev->needed_tailroom so underlying trailer/padding/ICV
requirements are honore…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-80925 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-80925" on the vendor's site.
CVE-2026-80925 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-80925 linux
- Ubuntu UBUNTU-CVE-2026-80925 linux
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com