Cyber Resilience

CVE-2026-43447

Memory Safety in Linux Kernel 6.15 – 6.18.19

Published
08 May 2026
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0012 3th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-43447 is a high-severity Use After Free (CWE-416) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

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.

EU & UK References

Vulnerability Data

In the Linux kernel, the following vulnerability has been resolved: iavf: fix PTP use-after-free during reset Commit 7c01dbfc8a1c5f ("iavf: periodically cache PHC time") introduced a worker to cache PHC time, but failed to stop it during reset or disable. This…

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creates a race condition where `iavf_reset_task()` or `iavf_disable_vf()` free adapter resources (AQ) while the worker is still running. If the worker triggers `iavf_queue_ptp_cmd()` during teardown, it accesses freed memory/locks, leading to a crash. Fix this by calling `iavf_ptp_release()` before tearing down the adapter. This ensures `ptp_clock_unregister()` synchronously cancels the worker and cleans up the chardev before the backing resources are destroyed.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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.
Why these techniques?

UAF race during VF reset/disable triggers kernel crash, directly enabling local DoS via system exploitation.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

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CVE-2026-23351Same product: Linux Linux Kernel
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CVE-2026-31511Same product: Linux Linux Kernel
CVE-2026-45906Same product: Linux Linux Kernel
CVE-2026-31419Same product: Linux Linux Kernel
CVE-2026-45938Same product: Linux Linux Kernel

Affected Assets

linux
linux kernel
7.0 · 6.15 — 6.18.19 · 6.19 — 6.19.9

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SA-11 Developer Testing and Evaluation
  • SA-15 Development Process, Standards, and Tools
  • SA-8 Security and Privacy Engineering Principles
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.3

Mitigating Controls (NIST 800-53 r5) AI

prevent

Developer testing and evaluation (including concurrency and lifecycle testing) would have detected the missing worker cancellation in iavf_reset_task/iavf_disable_vf before the UAF was introduced.

prevent

Secure development processes and tools (static analysis, thread-safety checkers) directly target use-after-free conditions arising from unsynchronized worker threads and resource teardown.

prevent

Security engineering principles require explicit resource-lifecycle management and synchronization when introducing background workers, preventing the exact race that leaves the PHC worker running after AQ structures are freed.

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 directly incorporate memory-safety tooling and reviews that prevent most use-after-free defects.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover use-after-free issues via scanning or analysis but do not prevent their introduction.

PR.PS-02 partial match
prevents

Routine patching removes known use-after-free instances after they have been introduced in released software.

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.

detects

Security testing in development can detect use-after-free bugs before release.

prevents

Secure SDLC mandates memory-safety practices that reduce use-after-free defects.

prevents

Application security requirements can specify memory-management rules that mitigate use-after-free.

prevents

Secure architecture principles include memory-safety design choices that limit use-after-free exposure.

prevents

Secure coding standards directly prescribe avoidance of use-after-free patterns.

prevents

Change-management processes help ensure memory-safety fixes are deployed consistently.

References