Use-after-free in Linux kernel - CVE-2026-98506

Vulnerability identifier: #VU156807

CSH Severity: Low

CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98506

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to corrupt kernel memory, potentially causing a denial of service.

The vulnerability exists due to improper folio lifetime management in dissolve_free_hugetlb_folio() in mm/hugetlb.c when dissolving gigantic pages without runtime support. A local user can trigger affected dissolution operations to free a folio that remains on the free list; if vmemmap restoration fails, the add_hugetlb_folio() rollback corrupts that list, potentially causing a kernel crash.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/443628f755b35bf45044f68b970b65cd531c42fd
• https://git.kernel.org/stable/c/a363c62a653cc8b3e21da9545fa4e028ef50f9c3
• https://git.kernel.org/stable/c/ccf96a4b8626a001c13c5836d8357f31c57bbd8e
• https://git.kernel.org/stable/c/ddc1055b557506a6ea8930dfbd8d1555d6a3f01e

• Use-after-free in Linux kernel mm
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more