CVE-2025-40174

Stale TLB retention via missing memory barrier

Published Nov 12, 2025 · Updated Aug 5, 2026

TLB invalidation failure in Linux 6.14 through 6.17.4 allows local users to retain stale memory translations after a requested flush. In arch/x86/mm/tlb.c, switch_mm_irqs_off() can load tlb_gen without an intervening SMP memory barrier after storing loaded_mm, so it can miss a concurrent flush_tlb_mm_range() generation update. The flaw requires an x86 multiprocessor system and local low-privileged access; no public trigger or concrete postcondition for the stale mapping has been documented.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

TLB invalidation failure in Linux 6.14 through 6.17.4 allows local users to retain stale memory translations after a requested flush. In arch/x86/mm/tlb.c, switch_mm_irqs_off() can load tlb_gen without an intervening SMP memory barrier after storing loaded_mm, so it can miss a concurrent flush_tlb_mm_range() generation update. The flaw requires an x86 multiprocessor system and local low-privileged access; no public trigger or concrete postcondition for the stale mapping has been documented.

The record

CVE
CVE-2025-40174
Published
Nov 12, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 12, 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=209954cbc7d0ce1a190fc725d20ce303d74d2680 <0fe5e3f5fb75c5d88dad24dece3ee75e9d87adeb
  2. Affected versionversion=209954cbc7d0ce1a190fc725d20ce303d74d2680 <83b0177a6c4889b3a6e865da5e21b2c9d97d0551
  3. Affected versionversion=6.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=209954cbc7d0ce1a190fc725d20ce303d74d2680 <0fe5e3f5fb75c5d88dad24dece3ee75e9d87adeb; version=209954cbc7d0ce1a190fc725d20ce303d74d2680 <83b0177a6c4889b3a6e865da5e21b2c9d97d0551; version=6.14

Published CVSS scores

7.8Linux Kernel CVE TeamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/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

No sourced classifications are available.

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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