Reachable assertion in Linux kernel - CVE-2026-72173
Published: August 21, 2026
Vulnerability identifier: #VU144577
CSH Severity: Low
CVSS v4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-72173
CWE-ID: CWE-617
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to trigger a kernel warning.
The vulnerability exists due to a reachable stale assertion in pagemap_pmd_range_thp() in fs/proc/task_mmu.c when processing pagemap PMD entries. A local user can trigger processing of a PMD device-private entry to trigger a kernel warning.
The condition involves device-private entries at the PMD level.
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-2026-72173
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