CVE-2026-43400

Local denial of service via unbounded handle counts

Published May 8, 2026 · Updated May 8, 2026

Resource exhaustion in the Linux Kernel AMDGPU driver allows local users to trigger an out-of-memory condition via the signal ioctl. The amdgpu_userq_signal_ioctl handler passes three unbounded user-supplied handle counts to kernel array-copy allocation operations. This path requires local low-privileged access and enabled AMDGPU user queues; exhausting kernel memory can interrupt system service.

CVSS severity5.5
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in the Linux Kernel AMDGPU driver allows local users to trigger an out-of-memory condition via the signal ioctl. The amdgpu_userq_signal_ioctl handler passes three unbounded user-supplied handle counts to kernel array-copy allocation operations. This path requires local low-privileged access and enabled AMDGPU user queues; exhausting kernel memory can interrupt system service.

The record

CVE
CVE-2026-43400
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <46630d966b99b0fc6cb01fef4110587f3375a0c0
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6fff5204d8aa26b1be50b6427f833bd3e8899c4f
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ea78f8c68f4f6211c557df49174c54d167821962

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <46630d966b99b0fc6cb01fef4110587f3375a0c0; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6fff5204d8aa26b1be50b6427f833bd3e8899c4f; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ea78f8c68f4f6211c557df49174c54d167821962

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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