CVE-2026-64432: Linux kernel · fs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcns
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 15:59 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +44
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch addressing this vulnerability is available and should be applied. The fix validates the Dirty Page Table capacity during log replay to prevent out-of-bounds writes. Users should update to the fixed Linux kernel versions provided by their distribution vendors, such as those listed in the Ubuntu security notice USN-8726-1. No additional mitigations are specified or required beyond applying the official kernel updates.
Description
A vulnerability in the Linux kernel's NTFS3 filesystem driver (CVE-2026-64432) involves improper validation of the Dirty Page Table (DPT) capacity during $LogFile journal replay. This flaw can cause a kernel slab out-of-bounds write at mount time when processing crafted NTFS images, potentially leading to system crashes or privilege escalation. The issue arises from unchecked indexing when copying Logical Cluster Numbers (LCNs) into the DPT, allowing attacker-controlled fields to exceed allocated array bounds. The vulnerability has been addressed by adding proper bounds checks to validate target VCN deltas and LCN counts against DPT entry capacity. A patch is available and included in Linux kernel updates distributed by Ubuntu and other vendors.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64432 (opens in a new tab)
- git.kernel.org/stable/c/3aa96956ca2200674e2a8f9c23ec6ecd45e5010f (opens in a new tab)
- git.kernel.org/stable/c/57382ec6ac63b63dce2789e835fded28b698ae79 (opens in a new tab)
- git.kernel.org/stable/c/946046841013ebac8492ef49651c53638d7a9a6a (opens in a new tab)
- git.kernel.org/stable/c/964c3fae1dfc49dde5468eace940f199cda234e9 (opens in a new tab)
- git.kernel.org/stable/c/c6f9e804f73ef809529865fbc7256dd189ff8c33 (opens in a new tab)
- git.kernel.org/stable/c/cf28fc1658463d768657cf1c27a83980d4ba7ef2 (opens in a new tab)
- git.kernel.org/stable/c/f433acc85b86f327d03ba8b03a33c105c51053de (opens in a new tab)
- ubuntu.com/security/CVE-2026-64432 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64432 (opens in a new tab)
- git.kernel.org/linus/57382ec6ac63b63dce2789e835fded28b698ae79 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)