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Linux KernelOperating system · Linux

CVE-2026-46135

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-28
Fix available
A fix is available. Upgrade to 6.12.88 / 6.18.30 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

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
In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: fix race between ICReq handling and queue teardown nvmet_tcp_handle_icreq() updates queue->state after sending an Initialization Connection Response (ICResp), but it does so without serializing against target-side queue teardown. If an NVMe/TCP host sends an Initialization Connection Request (ICReq) and immediately closes the connection, target-side teardown may start in softirq context before io_work drains the already buffered ICReq. In that case, nvmet_tcp_schedule_release_queue() sets queue->state to NVMET_TCP_Q_DISCONNECTING and drops the queue reference under state_lock. If io_work later processes that ICReq, nvmet_tcp_handle_icreq() can still overwrite the state back to NVMET_TCP_Q_LIVE. That defeats the DISCONNECTING-state guard in nvmet_tcp_schedule_release_queue() and allows a later socket state change to re-enter teardown and issue a second kref_put() on an already released queue. The ICResp send failure path has the same problem. If teardown has already moved the queue to DISCONNECTING, a send error can still overwrite the state with NVMET_TCP_Q_FAILED, again reopening the window for a second teardown path to drop the queue reference. Fix this by serializing both post-send state transitions with state_lock and bailing out if teardown has already started. Use -ESHUTDOWN as an internal sentinel for that bail-out path rather than propagating it as a transport error like -ECONNRESET. Keep nvmet_tcp_socket_error() setting rcv_state to NVMET_TCP_RECV_ERR before honoring that sentinel so receive-side parsing stays quiesced until the existing release path completes.

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 · high confidence

Race condition in Linux kernel's NVMe/TCP target where nvmet_tcp_handle_icreq() can overwrite queue state to LIVE after teardown has already set it to DISCONNECTING, defeating the guard against double kref_put() on the queue reference. This creates a use-after-free scenario when the second teardown path attempts to release an already-freed queue structure.

MitigationApply the kernel patch which adds state_lock serialization around post-send state transitions and bails out with -ESHUTDOWN if teardown has already begun. This is a kernel-level fix requiring kernel source update and reboot to apply.

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
Linux KernelOperating system
Affected:>= 5.0, < 6.12.88>= 6.13, < 6.18.30>= 6.19, < 7.0.7= 7.1

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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. Check kernel version
    Run 'uname -r' to get the running kernel version and compare it to the affected ranges: >= 5.0, < 6.12.88; >= 6.13, < 6.18.30; >= 6.19, < 7.0.7; = 7.1
    Affected if The kernel version falls within any of the affected version ranges
  2. Verify NVMe/TCP target module is loaded
    Run 'lsmod | grep nvmet_tcp' or check /sys/module/nvmet_tcp to see if the nvmet_tcp kernel module is loaded
    Affected if The nvmet_tcp module is loaded in memory
  3. Check for active NVMe/TCP target queues
    Inspect /sys/kernel/config/nvmet/ for active NVMe over Fabrics target configurations, or check /proc/cmdline for kernel command-line parameters related to NVMe target, or use 'ss -tlnp | grep 4420' to listen for NVMe/TCP port 4420
    Affected if There are active NVMe/TCP target listeners or established connections
  4. Determine if system acts as NVMe target
    Check if the kernel config includes CONFIG_NVME_TARGET=y or CONFIG_NVME_TARGET=m by looking at /boot/config-$(uname -r) or /proc/config.gz if available, and verify the target subsystem is initialized
    Affected if The kernel has NVMe target support enabled and the subsystem is initialized

A system is affected only if it runs an affected kernel version AND has the NVMe/TCP target subsystem active with at least one configured queue.

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
Upgrade available Upgrade to 6.12.88 / 6.18.30 / 7.0.7 or later
Fixed in 6.12.886.18.307.0.7
Vendor patch git.kernel.org →
Interim mitigation

Apply the kernel patch which adds state_lock serialization around post-send state transitions and bails out with -ESHUTDOWN if teardown has already begun. This is a kernel-level fix requiring kernel source update and reboot to apply.

Recommended fix High confidence

Upgrade to Linux kernel 6.12.88+, 6.18.30+, or 7.0.7+ (or 7.1.x once a fix is released)

  1. 1. Identify the currently running kernel version using `uname -r`
  2. 2. Back up critical data and configuration files before performing kernel upgrade
  3. 3. Update package repository metadata: `sudo apt-get update` (Debian/Ubuntu) or `sudo yum/dnf check-update` (RHEL/Fedora)
  4. 4. Install the fixed kernel version appropriate for your distribution: For Ubuntu/Debian, use `sudo apt-get install linux-image-<version>`; for RHEL/Fedora, use `sudo dnf install kernel-<version>`
  5. 5. If the fixed version is not available in your distribution's repositories, obtain the upstream kernel source from https://www.kernel.org/ and compile version 6.12.88, 6.12.89, 6.18.30, 6.18.31, 7.0.7, or 7.0.8
  6. 6. Update bootloader configuration (GRUB) to ensure the new kernel is selected at boot: `sudo update-grub` or `sudo grub2-mkconfig -o /boot/grub2/grub.cfg`
  7. 7. Reboot the system into the new kernel: `sudo reboot`
  8. 8. After reboot, verify the running kernel is now >= 6.12.88, >= 6.18.30, or >= 7.0.7 using `uname -r`
Caveat Kernel upgrades may require recompilation of third-party kernel modules (drivers). Ensure vendor drivers are compatible with the target kernel version before upgrading. Test in staging environment first.

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

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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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-2026-46135 in production — separate from our analysis above.

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What this is

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