Out-of-bounds read in Linux kernel - CVE-2026-68172
Published: August 12, 2026
Vulnerability identifier: #VU142144
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-2026-68172
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in huge_ptep_get()/find_num_contig in arch/arm64/mm/hugetlbpage.c when handling unaligned addresses within contpmd/contpte-mapped hugetlb folios. A local user can trigger the kernel to process such an address to cause a denial of service.
This can cause the kernel to iterate beyond the PTE table and dereference an invalid pointer, which may panic the kernel. The issue is specific to arm64 systems, and incorrect CONT_PTES versus CONT_PMDS handling is noted on systems using 16K page size.
Affected software
Linux kernel
Ubuntu
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
Ubuntu
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
How to mitigate CVE-2026-68172
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1