Double free in Linux kernel - CVE-2026-31686
Published: April 27, 2026
Vulnerability identifier: #VU128250
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-31686
CWE-ID: CWE-415
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a double free in kasan_free_pxd() when freeing kasan page table entries during memory unmapping. A local user can trigger the vulnerable code path to cause a denial of service.
The issue was observed on powerpc systems with 64K page size where PUD tables can be allocated from the pgtable-2^9 slab cache.
How to mitigate CVE-2026-31686
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/51d8c78be0c27ddb91bc2c0263941d8b30a47d3b
- https://git.kernel.org/stable/c/85d98614e089a67dc6faa8ca766fe10a639f82b4
- https://git.kernel.org/stable/c/a05f77cb227c39c5069aea6f12762a29d1e6c103
- https://git.kernel.org/stable/c/b38237a2ea9c6c19836eee2c57037e1f9f103576
- https://git.kernel.org/stable/c/cec74b2ab7dff866b1d77eaa545b9e8fd14a1f87
- https://git.kernel.org/stable/c/f6204f7ff6aff62ce6242a76982c5ba3a9ded707