CVE-2026-64417: Linux kernel · mm: shrinker: fix NULL pointer dereference in debugfs shrinker_debugfs_add() creates
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-147.147 : update Linux kernel when convenient.
Data as of 30 Oct 2026, 06:59 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 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1 +28
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- 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)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
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 is available and fixed versions include Linux kernel releases 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1, 6.8.0-1071.79, and others as listed. Users should upgrade to these fixed kernel versions to remediate the vulnerability. No additional mitigation is necessary once patched.
Description
A NULL pointer dereference vulnerability in the Linux kernel's memory management shrinker debugfs interface was fixed. The flaw occurs because debugfs files 'count' and 'scan' are created unconditionally, assuming both count_objects() and scan_objects() callbacks are implemented by every shrinker. Some shrinkers, such as the xen-backend, implement only one callback, leading to kernel panic when writing to the missing callback's debugfs file. The fix ensures these debugfs files are only created if the corresponding callbacks exist.
References
- ubuntu.com/security/CVE-2026-64417 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64417 (opens in a new tab)
- git.kernel.org/linus/e30453c61e185e914fde83c650e268067b140218 (opens in a new tab)
- git.kernel.org/stable/c/006467ab932698612398f853344a7405164541f4 (opens in a new tab)
- git.kernel.org/stable/c/09d2407985b8ce3e831f9d4310fe7ac06a6b3ae9 (opens in a new tab)
- git.kernel.org/stable/c/36f8534f461222291a74156ab91f3ba9f09b6f93 (opens in a new tab)
- git.kernel.org/stable/c/b9beed2322f3538b0d2d53307062da4102b8d8d8 (opens in a new tab)
- git.kernel.org/stable/c/e30453c61e185e914fde83c650e268067b140218 (opens in a new tab)
- git.kernel.org/stable/c/ebb45c2648b1f60715fd283700f651e05e431231 (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)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)