CVE-2026-31686

Local kernel crash via misaligned page-table free

Published Apr 27, 2026 · Updated Apr 27, 2026

Double free in Linux Kernel KASAN allows local users with CAP_SYS_ADMIN to crash the kernel during PMEM unbind or memory hotplug. kasan_free_pxd() converts a slab-backed 4 KiB PUD table through page_to_virt(pxd_page()), incorrectly assuming page alignment on PowerPC systems with 64 KiB pages. The demonstrated path requires PowerPC, 64 KiB pages, KASAN, PMEM, and root-equivalent capability access; triggering it interrupts service by crashing the kernel.

CVSS severity7.8
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double free in Linux Kernel KASAN allows local users with CAP_SYS_ADMIN to crash the kernel during PMEM unbind or memory hotplug. kasan_free_pxd() converts a slab-backed 4 KiB PUD table through page_to_virt(pxd_page()), incorrectly assuming page alignment on PowerPC systems with 64 KiB pages. The demonstrated path requires PowerPC, 64 KiB pages, KASAN, PMEM, and root-equivalent capability access; triggering it interrupts service by crashing the kernel.

The record

CVE
CVE-2026-31686
Published
Apr 27, 2026
Updated
Apr 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-415, T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0207df4fa1a869281ddbf72db6203dbf036b3e1a <51d8c78be0c27ddb91bc2c0263941d8b30a47d3b
  2. Affected versionversion=0207df4fa1a869281ddbf72db6203dbf036b3e1a <85d98614e089a67dc6faa8ca766fe10a639f82b4
  3. Affected versionversion=0207df4fa1a869281ddbf72db6203dbf036b3e1a <a05f77cb227c39c5069aea6f12762a29d1e6c103
  4. Affected versionversion=0207df4fa1a869281ddbf72db6203dbf036b3e1a <b38237a2ea9c6c19836eee2c57037e1f9f103576
  5. Affected versionversion=0207df4fa1a869281ddbf72db6203dbf036b3e1a <cec74b2ab7dff866b1d77eaa545b9e8fd14a1f87
  6. Affected versionversion=0207df4fa1a869281ddbf72db6203dbf036b3e1a <f6204f7ff6aff62ce6242a76982c5ba3a9ded707
  7. Affected versionversion=4.19

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0207df4fa1a869281ddbf72db6203dbf036b3e1a <51d8c78be0c27ddb91bc2c0263941d8b30a47d3b; version=0207df4fa1a869281ddbf72db6203dbf036b3e1a <85d98614e089a67dc6faa8ca766fe10a639f82b4; version=0207df4fa1a869281ddbf72db6203dbf036b3e1a <a05f77cb227c39c5069aea6f12762a29d1e6c103; version=0207df4fa1a869281ddbf72db6203dbf036b3e1a <b38237a2ea9c6c19836eee2c57037e1f9f103576; version=0207df4fa1a869281ddbf72db6203dbf036b3e1a <cec74b2ab7dff866b1d77eaa545b9e8fd14a1f87; version=0207df4fa1a869281ddbf72db6203dbf036b3e1a <f6204f7ff6aff62ce6242a76982c5ba3a9ded707; version=4.19

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double Free
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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