Vulnary
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Critical· 9.8official fix available

CVE-2025-40343

A flaw in the Linux kernel's NVMe over Fabrics target (nvmet-fc) could cause an association deletion work item to be scheduled twice when a port is forcefully shut down via configfs. Because the association list is an RCU list, the second scheduling could operate on already‑freed memory, leading to a use‑free condition that might allow privilege escalation or denial of service. The issue has been fixed by adding a terminating flag to prevent double scheduling.

publishedDec 9, 2025
last modifiedJul 30, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
44th percentile · chance of exploitation in 30 days
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →
auto-deletes from the system
counting…on Aug 29, 2026

An official fix is available, so this entry is kept for 30 days and then removed automatically.

01

Who is affected

Linux systems using the NVMe over Fabrics target (nvmet-fc) feature.

02

Real-world impact

An attacker with the ability to trigger a forceful port shutdown could potentially execute arbitrary code with kernel privileges or crash the system.

03

Why this severity

The CVSS v3.1 base score is 9.8 (Critical) due to network‑adjacent attack vector, low complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability.

04

What to do about it

official fix available
recommended steps
  1. 011. Obtain the Linux kernel patch that resolves CVE-2025-40343 from your distribution's security updates.
  2. 022. Install or update the kernel according to your vendor's instructions.
  3. 033. Reboot the system to load the patched kernel.

NVD description states the vulnerability has been resolved in the Linux kernel.

05

Timeline

  1. Dec 9, 2025 · Dec 9, 2025
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Jul 30, 2026 · 6d ago
    Advisory updated
    The NVD record was last revised.
  3. Jul 30, 2026 · 6d ago
    Official fix available
    A vendor patch or mitigation now exists — see the remediation steps above.
06

How it’s attacked

Attack vectorNetwork (remote)
Attack complexityLow
Privileges requiredNone
User interactionNone needed
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
07

References & advisories

(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →