CVE-2026-64216: Linux kernel · netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 7.0.0-28.28~24.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-28.28~24.04.1, 7.0.0-28.28, 7.0.0-1009.9 +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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.
Patches and advisories
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 promptly. The Ubuntu security advisory USN-8618-1 confirms that fixes have been released for affected Linux kernel versions. Users should update their Linux kernel packages to the fixed versions provided by their distribution vendors. No additional mitigations are specified by the vendor advisory.
Description
A use-after-free (UAF) vulnerability in the Linux kernel's netfs subsystem was fixed in netfs_unlock_abandoned_read_pages() and netfs_unlock_read_folio() functions. The flaw involved improper handling of folio pointers after clearing the NETFS_RREQ_IN_PROGRESS flag, potentially leading to dereferencing freed memory. This vulnerability has a high CVSS score of 9.8, indicating critical impact on confidentiality, integrity, and availability. Multiple Linux kernel versions, including various 4.15.x, 5.0.x, 5.3.x, and 7.0.0 builds, are affected. A patch is available and has been released by vendors such as Ubuntu.
References
- ubuntu.com/security/CVE-2026-64216 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64216 (opens in a new tab)
- git.kernel.org/linus/dbe556972100fabb8e5a1b3d2163831ff07b1e8e (opens in a new tab)
- git.kernel.org/stable/c/3866d015f33aeedf81338dd99154703bef33faef (opens in a new tab)
- git.kernel.org/stable/c/6080fa3ecfbb4448a3b47368629534c09b6ec750 (opens in a new tab)
- git.kernel.org/stable/c/dbe556972100fabb8e5a1b3d2163831ff07b1e8e (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)