CVE-2026-4652
Kernel Panic via Invalid CNTLID in NVMe/TCP Causes DoS
Publication date: 2026-03-26
Last updated on: 2026-04-30
Assigner: FreeBSD
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| freebsd | freebsd | 15.0 |
| freebsd | freebsd | 15.0 |
| freebsd | freebsd | 15.0 |
| freebsd | freebsd | 15.0 |
| freebsd | freebsd | 15.0 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-476 | The product dereferences a pointer that it expects to be valid but is NULL. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
CVE-2026-4652 is a remote denial of service vulnerability in the FreeBSD operating system's NVMe over Fabrics implementation, specifically in the nvmf kernel module.
The issue occurs when a remote client sends a CONNECT command for an I/O queue with an invalid or stale CNTLID (controller identifier) to a system exposing an NVMe/TCP target.
This causes a null pointer dereference in the kernel, which triggers a kernel panic and results in an unauthenticated denial of service condition on the affected machine.
How can this vulnerability impact me? :
An attacker with network access to the NVMe/TCP target can exploit this vulnerability to cause the affected FreeBSD system to crash unexpectedly.
This results in an unauthenticated Denial of Service (DoS), making the system unavailable until it is rebooted.
There is no workaround available, so the only mitigation is to upgrade the system to a patched version and reboot.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
There is no specific information provided about detection methods or commands to identify this vulnerability on a network or system.
What immediate steps should I take to mitigate this vulnerability?
To mitigate CVE-2026-4652, you must upgrade your FreeBSD system to a version released after the fix dates and then reboot.
- If your system was installed from base system packages (15.0-RELEASE on amd64 or arm64), run the following commands:
- pkg upgrade -r FreeBSD-base
- shutdown -r +10min "Rebooting for a security update"
- If your system was installed from binary distribution sets, run:
- freebsd-update fetch
- freebsd-update install
- shutdown -r +10min "Rebooting for a security update"
- Alternatively, apply the source code patch by downloading it, verifying its PGP signature, applying the patch, recompiling the kernel, and rebooting.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify any direct impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.