Vulnerability in Linux kernel (CVE-2026-90083)
Summary
Vulnerability in Linux kernel (CVE-2026-90083). 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:
net/sched: act_ife: Only operate on Ethernet frames
act_ife encapsulates/decapsulates the original Ethernet header and uses
skb->dev->hard_header_len as the length of that header. That is only
correct for Ethernet devices: on a device where hard_header_len does not
match the L2 header that was actually pulled (PPP reports PPP_HDRLEN
while nothing is stripped on ingress), the ingress skb_push()/skb_pull()
use the wrong length and can hit skb_under_panic when headroom is tight.
IFE is Ethernet-only by design - it builds an outer ethhdr, rewrites
h_source/h_dest/h_proto, and calls eth_type_trans() on decode - so
instead of trying to make the offsets work for arbitrary link types,
simply drop packets that do not carry an Ethernet header.
Checking skb->dev->type alone is not enough. We have to cater for a
corner case where mirred can redirect an skb from a non-Ethernet device
to an Ethernet one, and skb->dev then says nothing about the framing the
skb actually has: an skb redirected from ppp0 reaches the target's ingress
hook with mac_len 0 and no Ethernet header at all. So at ingress also
require mac_len to be ETH_HLEN. On egress mac_len is not maintained, so
the device type is all we have; a bogus redirect there yields a malformed
frame rather than an out-of-bounds push, and it would be malformed with or
without IFE.
That corner case is not theoretical - redirecting from ppp0 into a veth
that has an ife enc…
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-2026-90083 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-2026-90083" on the vendor's site.
CVE-2026-90083 (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。
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com