Vulnerability in Linux kernel (CVE-2026-90051)
Summary
Vulnerability in Linux kernel (CVE-2026-90051). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
tcp: reject non zerocopy devmem tx
Devmem tcp tx doesn't work without zero-copy, however it's not currently
enforced if NETIF_F_SG isn't present. In this case, tcp_sendmsg_locked()
will try the copy path and try to copy data from an iovec which consists
of offsets into the dma-buf and would normally fail. Moreover,
d9c56501c72fd ("net: tcp: block mixing readable and unreadable frags")
relies on that and assumes that the devmem binding is present IFF we're
using the zero-copy path, which can be used to mix net-iov and pages in
a single skb, and break invariants. Let's reject devmem tx without
zero-copy.
Note, the parameter check the patch is modifying is too loose, we can
create an io_uring request with dmabuf_id and all ZC flags, but which
won't have the binding. We replace it with stricter validation.
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-2026-90051 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-90051" on the vendor's site.
CVE-2026-90051 (Linux kernel) — CVSS v3 7.8
Attack vector: local / no user interaction
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: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-90051 linux Fixed in: 7.2.6-1
- Ubuntu UBUNTU-CVE-2026-90051 linux-hwe-edge
References
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com