Vulnerability in Linux kernel (CVE-2026-46289)
Summary
Vulnerability in Linux kernel (CVE-2026-46289). 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:
lib/scatterlist: fix length calculations in extract_kvec_to_sg
Patch series "Fix bugs in extract_iter_to_sg()", v3.
Fix bugs in the kvec and user variants of extract_iter_to_sg. This series
is growing due to useful remarks made by sashiko.dev.
The main bugs are:
- The length for an sglist entry when extracting from
a kvec can exceed the number of bytes in the page. This
is obviously not intended. - When extracting a user buffer the sglist is temporarily
used as a scratch buffer for extracted page pointers.
If the sglist already contains some elements this scratch
buffer could overlap with existing entries in the sglist.
The series adds test cases to the kunit_iov_iter test that demonstrate all
of these bugs. Additionally, there is a memory leak fix for the test
itself.
The bugs were orignally introduced into kernel v6.3 where the function
lived in fs/netfs/iterator.c. It was later moved to lib/scatterlist.c in
v6.5. Thus the actual fix is only marked for backports to v6.5+.
This patch (of 5):
When extracting from a kvec to a scatterlist, do not cross page
boundaries. The required length was already calculated but not used as
intended.
Adjust the copied length if the loop runs out of sglist entries without
extracting everything.
While there, return immediately from extract_iter_to_sg if there are no
sglist entries at all.
A subsequent commit will add kunit test cases that demonstrate…
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-2026-46289 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-46289" on the vendor's site.
CVE-2026-46289 (Linux kernel) — CWE-401 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / 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 (CWE-401) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: Critical (CVSS 9.8/10). 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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-46289 linux-lts Fixed in: 6.12.92-r0
- Debian DEBIAN-CVE-2026-46289 linux Fixed in: 6.12.88-1
- Ubuntu UBUNTU-CVE-2026-46289 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