dbcve.org
Linux KernelOperating system · Linux

CVE-2026-31436

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-22
Fix available
A fix is available. Upgrade to 6.12.80 / 6.18.21 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: dmaengine: idxd: fix possible wrong descriptor completion in llist_abort_desc() At the end of this function, d is the traversal cursor of flist, but the code completes found instead. This can lead to issues such as NULL pointer dereferences, double completion, or descriptor leaks. Fix this by completing d instead of found in the final list_for_each_entry_safe() loop.

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

In the Linux kernel's idxd DMA engine driver, the llist_abort_desc() function has a logic error where it completes the wrong descriptor. The traversal cursor 'd' holds the current list entry, but the code incorrectly completes 'found' (a previous descriptor) instead. This can cause NULL pointer dereferences when accessing stale pointers, double completion leading to use-after-free, or descriptor leaks where DMA descriptors are never properly released.

MitigationApply the upstream kernel patch to correct the completion to use variable 'd' instead of 'found', then update the kernel and reboot. For production systems, verify DMA operations complete correctly after the update.

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:>= 6.8, < 6.12.80>= 6.13, < 6.18.21>= 6.19, < 6.19.11= 7.0

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
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 running kernel version
    Run `uname -r` to get the installed kernel version
    Affected if The version falls within any of these ranges: >= 6.8 and < 6.12.80; >= 6.13 and < 6.18.21; >= 6.19 and < 6.19.11; or equals 7.0
  2. Verify idxd driver is in use
    Run `lsmod | grep idxd` or check if /sys/bus/dsa/devices/ exists and contains devices
    Affected if The idxd/dsa driver module is loaded or the idxd device directory exists in /sys/bus/dsa/
  3. Inspect llist_abort_desc function code
    Locate the idxd driver source (typically in drivers/dma/idxd/*.c) and examine the llist_abort_desc() function; look for the list_for_each_entry_safe loop and identify which variable is passed to idxd_complete_desc()
    Affected if The function completes the variable 'found' instead of the loop cursor 'd', indicating the buggy code is present
  4. Confirm kernel source version matches running kernel
    Check /proc/version or use `cat /usr/src/linux-$(uname -r)/include/generated/uapi/linux/version.h 2>/dev/null` if kernel headers are installed
    Affected if The running kernel version matches an affected version range and the buggy code pattern is confirmed

A system is affected if it runs a kernel version in the affected ranges AND has the idxd/dsa driver loaded/enabled AND the llist_abort_desc() function contains the bug where 'found' is completed instead of 'd'.

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 6.12.80 / 6.18.21 / 6.19.11 or later
Fixed in 6.12.806.18.216.19.11
Vendor patch git.kernel.org →
Interim mitigation

Apply the upstream kernel patch to correct the completion to use variable 'd' instead of 'found', then update the kernel and reboot. For production systems, verify DMA operations complete correctly after the update.

Recommended fix High confidence

Upgrade to Linux kernel 6.12.80, 6.18.21, 6.19.11, or 7.1 (or later stable releases)

  1. Identify the current running kernel version using `uname -r`
  2. Download or obtain the patched kernel version for your distribution: 6.12.80 or later for 6.12.x kernels, 6.18.21 or later for 6.13-6.18.x kernels, 6.19.11 or later for 6.19.x kernels, or 7.1 or later for 7.0 kernels
  3. Apply the kernel upgrade via your distribution's package manager (e.g., `apt update && apt upgrade` for Debian/Ubuntu, `dnf update` for Fedora/RHEL, or `pacman -Syu` for Arch)
  4. Reboot the system to load the patched kernel
  5. Verify the new kernel version is running with `uname -r` and confirm it matches a fixed release
Caveat Kernel upgrades may require rebooting services and could have minor compatibility issues with external kernel modules; ensure third-party drivers (like NVIDIA drivers) are recompiled for the new kernel version

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
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-31436 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2026-31436 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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