Cyber Posture

CVE-2026-31389

High

Published: 03 April 2026

Published
03 April 2026
Modified
27 April 2026
KEV Added
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Patch
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CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0001 3.5th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-31389 is a high-severity an unspecified weakness vulnerability in Kernel (inferred from references). Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 3.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and SI-16 (Memory Protection).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Privilege Escalation (T1068). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match
prevent

Directly requires timely patching of the use-after-free flaw in the Linux kernel SPI controller registration process.

SI-17 Fail-safe Procedures partial match
prevent

Mandates fail-safe procedures during resource allocation failures to ensure proper deregistration and avoid use-after-free.

SI-16 Memory Protection partial match
prevent

Implements memory safeguards that mitigate exploitation of the use-after-free vulnerability for code execution or crashes.

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
Why these techniques?

Use-after-free in Linux kernel SPI subsystem directly enables local privilege escalation via arbitrary code execution or kernel-level access from low-privileged context.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

In the Linux kernel, the following vulnerability has been resolved: spi: fix use-after-free on controller registration failure Make sure to deregister from driver core also in the unlikely event that per-cpu statistics allocation fails during controller registration to avoid use-after-free…

more

(of driver resources) and unclocked register accesses.

Deeper analysisAI

CVE-2026-31389 is a use-after-free vulnerability in the Linux kernel's SPI subsystem. It arises during SPI controller registration when per-CPU statistics allocation fails, leading to improper handling that can result in use-after-free of driver resources and unclocked register accesses. The issue affects the Linux kernel and carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

A local attacker with low privileges can exploit this vulnerability through low-complexity means without requiring user interaction. Exploitation could grant high-impact access to confidential data, modification of system integrity, and denial-of-service via availability disruption, such as through arbitrary code execution or kernel crashes triggered by the use-after-free.

Mitigation involves applying patches from Linux kernel stable repositories, as detailed in the referenced commits: 0e23f50086da7d0b183dfeac26021acfcdee086b, 23b51bad2eb8787aa74324cfccefb258515ae5ba, 6bbd385b30c7fb6c7ee0669e9ada91490938c051, 80f3e8cd2b4ad355b2ad2024cf423f6d183404f7, and 8634e05b08ead636e926022f4a98416e13440df9. These fixes ensure deregistration from the driver core occurs even if allocation fails during registration.

Details

CWE(s)
None listed

Affected Products

Kernel
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inferred from references and description; NVD did not file a CPE for this CVE

References