CVE-2022-49743Network attack vector

Remote kernel panic via crafted NFS filehandle

Published Mar 27, 2025 · Updated Aug 5, 2026

Denial of service in Linux kernel OverlayFS allows remote attackers to trigger a kernel panic through a crafted NFS filehandle. In ovl_fid_to_fh(), memcpy targets the fixed fb field rather than the enclosing buf flexible array, causing FORTIFY_SOURCE to flag a field-spanning write despite a sufficient allocation. The path requires an OverlayFS mount with nfs_export=on exported by nfsd, while a panic also requires CONFIG_FORTIFY_SOURCE and panic_on_warn.

CVSS severity7.5
High
EPSS probability0.44%
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 OverlayFS allows remote attackers to trigger a kernel panic through a crafted NFS filehandle. In ovl_fid_to_fh(), memcpy targets the fixed fb field rather than the enclosing buf flexible array, causing FORTIFY_SOURCE to flag a field-spanning write despite a sufficient allocation. The path requires an OverlayFS mount with nfs_export=on exported by nfsd, while a panic also requires CONFIG_FORTIFY_SOURCE and panic_on_warn.

The record

CVE
CVE-2022-49743
Published
Mar 27, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=5.5
  2. Affected versionversion=cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 <012cdef22000f3104e4fa8224ad29fde509b8caf
  3. Affected versionversion=cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 <07a96977b2f462337a9121302de64277b8747ab1
  4. Affected versionversion=cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 <a77141a06367825d639ac51b04703d551163e36c
  5. Affected versionversion=cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 <cf8aa9bf97cadf85745506c6a3e244b22c268d63

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.5; version=cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 <012cdef22000f3104e4fa8224ad29fde509b8caf; version=cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 <07a96977b2f462337a9121302de64277b8747ab1; version=cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 <a77141a06367825d639ac51b04703d551163e36c; version=cbe7fba8edfc8cb8e621599e376f8ac5c224fa72 <cf8aa9bf97cadf85745506c6a3e244b22c268d63

Published CVSS scores

7.5LinuxCVSS: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

T1499.004Application 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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