CVE-2026-53199Network attack vector

Remote guest crash via high-memory fragment misaddressing

Published Jun 25, 2026 · Updated Jun 25, 2026

Denial of service in Linux Kernel allows remote attackers to crash 32-bit x86 Hyper-V guests through network responses. netvsc_copy_to_send_buf passes a high-memory fragment PFN to phys_to_virt, then memcpy dereferences an address outside the direct map. Exposure requires CONFIG_HIGHMEM and a small outbound packet containing a high-memory-backed fragment; the resulting transmit-softirq fault is fatal.

CVSS severity7.5
High
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux Kernel allows remote attackers to crash 32-bit x86 Hyper-V guests through network responses. netvsc_copy_to_send_buf passes a high-memory fragment PFN to phys_to_virt, then memcpy dereferences an address outside the direct map. Exposure requires CONFIG_HIGHMEM and a small outbound packet containing a high-memory-backed fragment; the resulting transmit-softirq fault is fatal.

The record

CVE
CVE-2026-53199
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 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=3.16
  2. Affected versionversion=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <004e9ecfe6c5384f9e0b2f6f6389d42ec22789af
  3. Affected versionversion=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <09b8a7aa5a341bb345dc492aac139525efa13515
  4. Affected versionversion=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <0b38870d81ab3a04c1ab0598d9d3285f5d9d0584
  5. Affected versionversion=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <16514afeb7d3d121072ba9a0b640d6c1c5507db0
  6. Affected versionversion=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <695c59cf7bf707e6ff8cea01916ee50e86616933
  7. Affected versionversion=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <918c0c988239aa5ab96b254e504d191af6191061
  8. Affected versionversion=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <a82d4251918f37d9c5aab7b365157669fb885ec3
  9. Affected versionversion=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <fe7221b4346418d27ec2daccfc09df6692b76f0b

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.16; version=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <004e9ecfe6c5384f9e0b2f6f6389d42ec22789af; version=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <09b8a7aa5a341bb345dc492aac139525efa13515; version=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <0b38870d81ab3a04c1ab0598d9d3285f5d9d0584; version=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <16514afeb7d3d121072ba9a0b640d6c1c5507db0; version=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <695c59cf7bf707e6ff8cea01916ee50e86616933; version=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <918c0c988239aa5ab96b254e504d191af6191061; version=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <a82d4251918f37d9c5aab7b365157669fb885ec3; version=c25aaf814a63f9d9c4e45416f13d70ef0aa0be2e <fe7221b4346418d27ec2daccfc09df6692b76f0b

Published CVSS scores

7.5kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
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.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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