Out-of-Bounds Write in Linux kernel (CVE-2026-64432)
Summary
Out-of-bounds write in Linux kernel (CVE-2026-64432). 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:
fs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcns
In the analysis pass of $LogFile journal replay, log_replay() copies
LCNs from each action log record into an existing Dirty Page Table
(DPT) entry without bounding the destination index. A crafted NTFS
image with DPT entry lcns_follow=1 and an action log record with
lcns_follow=2 produces a kernel slab out-of-bounds write at mount
time:
BUG: KASAN: slab-out-of-bounds in log_replay+0x654c/0xdb60
Write of size 8 at addr ffff8880095e1040 by task mount
Two attacker-controlled fields can drive j+i past the allocated
page_lcns[] array:
- dp->lcns_follow (capacity) can be smaller than lrh->lcns_follow.
- lrh->target_vcn may be smaller than dp->vcn, making the u64
subtraction wrap to a huge size_t.
Validate target VCN delta and per-record LCN count against the
DPT entry capacity, bail via the existing out: cleanup label with
-EINVAL.
This mirrors the bounds-check pattern added in commit b2bc7c44ed17
("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot")
and commit 0ca0485e4b2e ("fs/ntfs3: validate rec->used in
journal-replay file record check").
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-2026-64432 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-2026-64432" on the vendor's site.
CVE-2026-64432 (Linux kernel) — CWE-787 / CVSS v3 7.8
Attack vector: local / unauthenticated
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.
Out-of-bounds write (CWE-787) 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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-64432 linux-lts Fixed in: 6.1.182-r0
- Debian DEBIAN-CVE-2026-64432 linux Fixed in: 6.1.180-1
- Ubuntu UBUNTU-CVE-2026-64432 linux-hwe-edge
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 git.kernel.org
- web git.kernel.org
- web github.com