CVE-2026-64533: Linux kernel · fs/ntfs3: validate lcns_follow in log_replay conversion
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, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% 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 +42
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 27 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
An official patch is available and should be applied to affected Linux kernel versions. The vulnerability has been fixed by validating the lcns_follow field during log_replay conversion to prevent out-of-bounds memory access. Users should update to patched kernel versions as provided by their Linux distribution vendors. No additional mitigation steps are required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's NTFS3 filesystem driver (log_replay function) allowed a malformed filesystem image to cause out-of-bounds memory access during conversion of directory entries. This was due to insufficient validation of the lcns_follow field, which controls memory copy length. The issue has been fixed by adding proper validation to prevent memory corruption.
References
- ubuntu.com/security/CVE-2026-64533 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64533 (opens in a new tab)
- git.kernel.org/linus/6a4c53a2e26a865565bd6a460961e8d6fcb32329 (opens in a new tab)
- git.kernel.org/stable/c/159f694d682e4215b3822ae31ed3a4631628fe55 (opens in a new tab)
- git.kernel.org/stable/c/32b9f8733feb241627fa5f564b1a99b5cae974c5 (opens in a new tab)
- git.kernel.org/stable/c/57c071e2c4f30b9c6f5aacb6679aab1269fbae99 (opens in a new tab)
- git.kernel.org/stable/c/6a4c53a2e26a865565bd6a460961e8d6fcb32329 (opens in a new tab)
- git.kernel.org/stable/c/7adb38279812c9c06b0e3fa7382f4d7887f3fa2d (opens in a new tab)
- git.kernel.org/stable/c/ca343a99806b4fc8e27c48f08be3445c5fcd1445 (opens in a new tab)
- git.kernel.org/stable/c/ddfc8683e1a627dbf1b83bacf8961443dd654258 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)