Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
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 OS Credential Dumping (T1003); ranked at the 5th 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
- 🇪🇺 ENISA EUVD: EUVD-2026-25886
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,…
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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
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Affected Assets
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.
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.