CVE-2026-89509

Kernel crash via zero-byte RDMA counter allocation

Published Sep 11, 2026 · Updated Sep 11, 2026

NULL-pointer dereference in Linux 6.18 allows attackers to crash the kernel via ionic RDMA counter allocation and binding. The ionic driver leaves size_rdma_counter unset, so rdma_zalloc_drv_obj() allocates zero bytes and alloc_and_bind() dereferences a null result. Reachability requires the ionic RDMA driver and RDMA-capable AMD Pensando DSC hardware; public sources identify no broader effect than a kernel crash.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL-pointer dereference in Linux 6.18 allows attackers to crash the kernel via ionic RDMA counter allocation and binding. The ionic driver leaves size_rdma_counter unset, so rdma_zalloc_drv_obj() allocates zero bytes and alloc_and_bind() dereferences a null result. Reachability requires the ionic RDMA driver and RDMA-capable AMD Pensando DSC hardware; public sources identify no broader effect than a kernel crash.

The record

CVE
CVE-2026-89509
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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=6.18
  2. Affected versionversion=ea4c399642b85dc30f44d90ee805c6a18fa03062 <08b8630b557828aedb1d9ef0a6e2ec421f334ee2
  3. Affected versionversion=ea4c399642b85dc30f44d90ee805c6a18fa03062 <c98197ee3cd28288da13dc9881bb9e74daa7cbbc
  4. Affected versionversion=ea4c399642b85dc30f44d90ee805c6a18fa03062 <cf3ebd89e754015625fee90aa938f6bc79a2c974

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.18; version=ea4c399642b85dc30f44d90ee805c6a18fa03062 <08b8630b557828aedb1d9ef0a6e2ec421f334ee2; version=ea4c399642b85dc30f44d90ee805c6a18fa03062 <c98197ee3cd28288da13dc9881bb9e74daa7cbbc; version=ea4c399642b85dc30f44d90ee805c6a18fa03062 <cf3ebd89e754015625fee90aa938f6bc79a2c974

Published CVSS scores

No CVSS assessment is available in this record.

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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