CVE-2022-49557

Host memory corruption via undersized guest FPU buffer

Published Feb 26, 2025 · Updated Aug 5, 2026

Out-of-bounds write in Linux kernel 5.17 KVM guest FPU handling allows local users to corrupt kernel memory through vCPU ioctls. fpu_copy_guest_fpstate_to_uabi allocates the host's smaller default FPU-state size but writes FP and SSE header bits beyond that buffer. Access to /dev/kvm on an x86 host without XSAVE is required; the overwrite can corrupt adjacent slab data and cause a kernel panic.

CVSS severity5.5
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Linux kernel 5.17 KVM guest FPU handling allows local users to corrupt kernel memory through vCPU ioctls. fpu_copy_guest_fpstate_to_uabi allocates the host's smaller default FPU-state size but writes FP and SSE header bits beyond that buffer. Access to /dev/kvm on an x86 host without XSAVE is required; the overwrite can corrupt adjacent slab data and cause a kernel panic.

The record

CVE
CVE-2022-49557
Published
Feb 26, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-787, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=5.17
  2. Affected versionversion=c60427dd50ba9b20063ccaed0e98d62e886d7a3b <9cf15ebb7dedfe2f27120743b8ea8441c99ac73c
  3. Affected versionversion=c60427dd50ba9b20063ccaed0e98d62e886d7a3b <c181acbd1a427859d5fda543b95fbae28f7f6068
  4. Affected versionversion=c60427dd50ba9b20063ccaed0e98d62e886d7a3b <d187ba5312307d51818beafaad87d28a7d939adf

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.17; version=c60427dd50ba9b20063ccaed0e98d62e886d7a3b <9cf15ebb7dedfe2f27120743b8ea8441c99ac73c; version=c60427dd50ba9b20063ccaed0e98d62e886d7a3b <c181acbd1a427859d5fda543b95fbae28f7f6068; version=c60427dd50ba9b20063ccaed0e98d62e886d7a3b <d187ba5312307d51818beafaad87d28a7d939adf

Published CVSS scores

5.5GitHub Advisory DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5UbuntuCVSS: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

CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service

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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