Improper Check or Handling of Exceptional Conditions in Linux kernel - CVE-2026-64181

Vulnerability identifier: #VU138432

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-64181

CWE-ID: CWE-703

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper handling of special page table mappings in __vm_normal_page() when processing huge PMD or PUD mappings on architectures without pmd_special()/pud_special() support. A local user can trigger memory management operations involving huge zero folios to cause a denial of service.

This issue is exposed on x86 32-bit systems with THP enabled.

Linux kernel
Ubuntu
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/62153767e8fc3889bc6508e9ffe927aaf64c4334
• https://git.kernel.org/stable/c/9052ea2ee2233be5d4786b8909151ca2bfbedf99
• https://git.kernel.org/stable/c/c0c6ccd9828c3a1950623b546fa57292a77b5c73

• Improper Check or Handling of Exceptional Conditions in Linux kernel mm
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia