dbcve.org
FreeBSDOperating system

CVE-2026-4652

HIGH · 7.5 CVSS v3.1 Published 2026-03-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
On a system exposing an NVMe/TCP target, a remote client can trigger a kernel panic by sending a CONNECT command for an I/O queue with a bogus or stale CNTLID. An attacker with network access to the NVMe/TCP target can trigger an unauthenticated Denial of Service condition on the affected machine.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A remote unauthenticated attacker with network access to an NVMe/TCP target can send a CONNECT command for an I/O queue containing a bogus or stale CNTLID, triggering a kernel panic and causing an unauthenticated Denial of Service condition.

MitigationApply kernel/OS vendor patches once available; meanwhile, restrict network access to NVMe/TCP targets using firewalls or network segmentation to limit exposure to remote attackers.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FreeBSDOperating system
Affected:= 15.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify FreeBSD version
    Run 'uname -r' or check /etc/os-release to confirm the installed FreeBSD version
    Affected if Version is exactly 15.0 (the only affected version listed)
  2. Confirm NVMe/TCP kernel support is present
    Check for loaded kernel modules related to NVMe/TCP using 'kldstat' or look for 'nvme' kernel modules in /boot/kernel/ or /boot/modules/
    Affected if NVMe/TCP kernel modules are present and loaded, as the vulnerability requires NVMe/TCP target functionality to be available
  3. Check for active NVMe/TCP target configuration
    Examine if the system is configured as an NVMe/TCP target by checking for nvmet-related configuration files, daemon processes, or network listeners on port 4420 (default NVMe/TCP port) using 'sockstat -4' or 'netstat -anp'
    Affected if The system is configured and listening as an NVMe/TCP target, exposing the vulnerable CONNECT command handler to network access
  4. Assess network exposure of NVMe/TCP service
    Review firewall rules (ipfw, pf, or ipf) and network configuration to determine if the NVMe/TCP port (4420/tcp) is accessible from untrusted networks
    Affected if The NVMe/TCP target port is accessible to unauthenticated remote attackers on the network

A system is affected if it runs FreeBSD 15.0 with NVMe/TCP target functionality enabled and exposed to network access, allowing remote unauthenticated attackers to trigger the kernel panic via malformed CONNECT commands.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply kernel/OS vendor patches once available; meanwhile, restrict network access to NVMe/TCP targets using firewalls or network segmentation to limit exposure to remote attackers.

Recommended fix Moderate confidence

FreeBSD 15.1 or later (check security.freebsd.org for the exact fixed release)

  1. Check security.freebsd.org for the specific Security Advisory (SA) related to this CVE
  2. Identify the fixed FreeBSD release by reviewing the advisory
  3. Backup all critical data before performing any system update
  4. Update the FreeBSD system to the fixed release using 'freebsd-update fetch' and 'freebsd-update install' or by rebuilding from source
  5. Reboot the system into the new kernel
  6. Verify the NVMe/TCP target is operational after the update
Caveat Kernel update may require rebuild of third-party kernel modules; review the Security Advisory for any configuration changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-4652 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data