CVE-2024-26603

System hang via undersized XSAVE fault-in range

Published Feb 24, 2024 · Updated May 11, 2026

Denial of service in the x86 FPU signal handler in Linux allows local users to hang the system via a crafted sigreturn frame. The restore path trusts user-controlled fx_sw->xstate_size when faulting in the XSAVE buffer, so fault_in_readable validates less memory than XRSTOR accesses and retries the same fault forever. A local user able to submit a sigreturn frame can consume kernel execution indefinitely, interrupting system availability without reading or changing data.

CVSS severity5.5
Medium
EPSS probability0.28%
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 the x86 FPU signal handler in Linux allows local users to hang the system via a crafted sigreturn frame. The restore path trusts user-controlled fx_sw->xstate_size when faulting in the XSAVE buffer, so fault_in_readable validates less memory than XRSTOR accesses and retries the same fault forever. A local user able to submit a sigreturn frame can consume kernel execution indefinitely, interrupting system availability without reading or changing data.

The record

CVE
CVE-2024-26603
Published
Feb 24, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 24, 2024CVE publishedPublication date reported by the CVE source.
  2. May 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=5.14
  2. Affected versionversion=fcb3635f5018e53024c6be3c3213737f469f74ff <627339cccdc9166792ecf96bc3c9f711a60ce996
  3. Affected versionversion=fcb3635f5018e53024c6be3c3213737f469f74ff <627e28cbb65564e55008315d9e02fbb90478beda
  4. Affected versionversion=fcb3635f5018e53024c6be3c3213737f469f74ff <8bd3eee7720c14b59a206bd05b98d7586bccf99a
  5. Affected versionversion=fcb3635f5018e53024c6be3c3213737f469f74ff <b2479ab426cef7ab79a13005650eff956223ced2
  6. Affected versionversion=fcb3635f5018e53024c6be3c3213737f469f74ff <d877550eaf2dc9090d782864c96939397a3c6835

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.14; version=fcb3635f5018e53024c6be3c3213737f469f74ff <627339cccdc9166792ecf96bc3c9f711a60ce996; version=fcb3635f5018e53024c6be3c3213737f469f74ff <627e28cbb65564e55008315d9e02fbb90478beda; version=fcb3635f5018e53024c6be3c3213737f469f74ff <8bd3eee7720c14b59a206bd05b98d7586bccf99a; version=fcb3635f5018e53024c6be3c3213737f469f74ff <b2479ab426cef7ab79a13005650eff956223ced2; version=fcb3635f5018e53024c6be3c3213737f469f74ff <d877550eaf2dc9090d782864c96939397a3c6835

Published CVSS scores

5.5OracleCVSS: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

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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