CVE-2025-68171

Cross-process AMX state disclosure via stale XFD synchronization

Published Dec 16, 2025 · Updated Dec 16, 2025

State-management failure in affected Linux kernel x86 FPU code allows local users to disclose or corrupt AMX tile state during signals. fpu__clear_user_states() reloads initial XSTATE after preemption without synchronizing fpstate::xfd to the CPU XFD MSR, leaving stale dynamic-feature state. Exploitation requires AMX/XFD-capable x86 hardware and a controlled preemption window; it can expose 8 KiB of another task's tile registers, corrupt computation, or panic hosts with panic_on_warn enabled.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

State-management failure in affected Linux kernel x86 FPU code allows local users to disclose or corrupt AMX tile state during signals. fpu__clear_user_states() reloads initial XSTATE after preemption without synchronizing fpstate::xfd to the CPU XFD MSR, leaving stale dynamic-feature state. Exploitation requires AMX/XFD-capable x86 hardware and a controlled preemption window; it can expose 8 KiB of another task's tile registers, corrupt computation, or panic hosts with panic_on_warn enabled.

The record

CVE
CVE-2025-68171
Published
Dec 16, 2025
Updated
Dec 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 16, 2025Record 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=5.16
  2. Affected versionversion=672365477ae8afca5a1cca98c1deb733235e4525 <1811c610653c0cd21cc9add14595b7cffaeca511
  3. Affected versionversion=672365477ae8afca5a1cca98c1deb733235e4525 <388eff894d6bc5f921e9bfff0e4b0ab2684a96e9
  4. Affected versionversion=672365477ae8afca5a1cca98c1deb733235e4525 <3f735419c4b43cde42e6d408db39137b82474e31
  5. Affected versionversion=672365477ae8afca5a1cca98c1deb733235e4525 <5b2619b488f1d08b960c43c6468dd0759e8b3035
  6. Affected versionversion=672365477ae8afca5a1cca98c1deb733235e4525 <eefbfb722042fc9210d2e0ac2b063fd1abf51895

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.16; version=672365477ae8afca5a1cca98c1deb733235e4525 <1811c610653c0cd21cc9add14595b7cffaeca511; version=672365477ae8afca5a1cca98c1deb733235e4525 <388eff894d6bc5f921e9bfff0e4b0ab2684a96e9; version=672365477ae8afca5a1cca98c1deb733235e4525 <3f735419c4b43cde42e6d408db39137b82474e31; version=672365477ae8afca5a1cca98c1deb733235e4525 <5b2619b488f1d08b960c43c6468dd0759e8b3035; version=672365477ae8afca5a1cca98c1deb733235e4525 <eefbfb722042fc9210d2e0ac2b063fd1abf51895

Published CVSS scores

7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5Amazon LinuxCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

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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