Cyber Resilience

CVE-2026-31689

Memory Safety in Linux Kernel 5.19 – 6.1.169

Published
27 April 2026
Modified
06 May 2026
Patch / advisory
CVSS Score v3.1 5.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0011 2th percentile
Risk Priority 40 floored blend · peak EPSS

Summary

CVE-2026-31689 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Linux Linux Kernel. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as Other Platforms; in the Not Applicable risk domain.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-31689 affects the Linux kernel's EDAC/mc subsystem in the edac_mc_alloc() function. The vulnerability arises from incorrect error path ordering: when the mci->pvt_info allocation fails, put_device() is called before device_initialize(), leading to kobject_put() on an uninitialized kobject and resulting in kernel warnings. This issue was observed in kernel version 7.0.0-rc1 during amd64_edac module initialization.

The vulnerability triggers in error paths during EDAC operations, as seen in a kernel trace involving systemd-udevd on CPU 22. Local system processes like udevd can encounter it under allocation failure conditions, producing warnings such as "kobject: '(null)': is not initialized, yet kobject_put() is being called" and stack traces from edac_mc_alloc() and amd64_edac_init(). No specific exploitation for code execution or escalation is detailed.

Kernel stable patches address the issue by reordering the initialization sequence to ensure device_initialize() precedes potential error paths that call put_device(). Relevant commits include https://git.kernel.org/stable/c/51520e03e70d6c73e33ee7cbe0319767d05764fe, https://git.kernel.org/stable/c/75825648ce984ca4cebb28e4bd2bf8c3a7e837c5, https://git.kernel.org/stable/c/87ce8ae511962e105bcb3534944208c6a9471ed9, https://git.kernel.org/stable/c/aae95970fad2127a1bd49d8713c7cd0677dcd2d6, and https://git.kernel.org/stable/c/d20e98c2df9354cc744431ad8ccbf49405b8b40f.

This vulnerability was identified by Claude while reviewing another EDAC patch, with no reported real-world exploitation.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

In the Linux kernel, the following vulnerability has been resolved: EDAC/mc: Fix error path ordering in edac_mc_alloc() When the mci->pvt_info allocation in edac_mc_alloc() fails, the error path will call put_device() which will end up calling the device's release function. However,…

more

the init ordering is wrong such that device_initialize() happens *after* the failed allocation and thus the device itself and the release function pointer are not initialized yet when they're called: MCE: In-kernel MCE decoding enabled. ------------[ cut here ]------------ kobject: '(null)': is not initialized, yet kobject_put() is being called. WARNING: lib/kobject.c:734 at kobject_put, CPU#22: systemd-udevd CPU: 22 UID: 0 PID: 538 Comm: systemd-udevd Not tainted 7.0.0-rc1+ #2 PREEMPT(full) RIP: 0010:kobject_put Call Trace: <TASK> edac_mc_alloc+0xbe/0xe0 [edac_core] amd64_edac_init+0x7a4/0xff0 [amd64_edac] ? __pfx_amd64_edac_init+0x10/0x10 [amd64_edac] do_one_initcall ... Reorder the calling sequence so that the device is initialized and thus the release function pointer is properly set before it can be used. This was found by Claude while reviewing another EDAC patch.

CWE(s)

AI Security AnalysisAI

AI Category
Other Platforms
Risk Domain
Not Applicable
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: claude

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
T1489 Service Stop Impact
Adversaries may stop or disable services on a system to render those services unavailable to legitimate users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-23309Same product: Linux Linux Kernel
CVE-2024-26784Same product: Linux Linux Kernel
CVE-2024-49920Same product: Linux Linux Kernel
CVE-2023-53458Same product: Linux Linux Kernel
CVE-2025-22086Same product: Linux Linux Kernel
CVE-2025-22093Same product: Linux Linux Kernel
CVE-2023-52782Same product: Linux Linux Kernel
CVE-2025-38308Same product: Linux Linux Kernel
CVE-2024-43855Same product: Linux Linux Kernel
CVE-2024-58066Same product: Linux Linux Kernel

Affected Assets

linux
linux kernel
7.0 · 5.19 — 6.1.169 · 6.2 — 6.6.135 · 6.7 — 6.12.82

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including static analysis) directly finds null-dereference bugs before deployment.

Documented development standards and tools can enforce null-safety rules and safe pointer usage.

Engineering principles can mandate defensive coding such as explicit null checks before dereference.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect NULL dereference defects before release.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References