CVE-2025-40336

Unintended memory access via unclamped huge-page mapping

Published Dec 9, 2025 · Updated Aug 5, 2026

Improper GPU memory mapping in Linux 6.15 through 6.17.7 allows local users to map memory outside the requested HMM range. drm_gpusvm_check_pages() and drm_gpusvm_range_get_pages() use hmm_pfn_to_map_order() without clamping the huge-page order to the current PFN index and range length. Access requires a low-privileged local user to reach the Xe DRM render-node ioctl path with a partially covered huge page; the resulting GPU mapping can expose or modify unintended memory and disrupt the host.

CVSS severity8.8
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper GPU memory mapping in Linux 6.15 through 6.17.7 allows local users to map memory outside the requested HMM range. drm_gpusvm_check_pages() and drm_gpusvm_range_get_pages() use hmm_pfn_to_map_order() without clamping the huge-page order to the current PFN index and range length. Access requires a low-privileged local user to reach the Xe DRM render-node ioctl path with a partially covered huge page; the resulting GPU mapping can expose or modify unintended memory and disrupt the host.

The record

CVE
CVE-2025-40336
Published
Dec 9, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 9, 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=6.15
  2. Affected versionversion=99624bdff8670795b678eafa6509aaad3a5c0175 <08e9fd78ba1b9e95141181c69cc51795c9888157
  3. Affected versionversion=99624bdff8670795b678eafa6509aaad3a5c0175 <c50729c68aaf93611c855752b00e49ce1fdd1558

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.15; version=99624bdff8670795b678eafa6509aaad3a5c0175 <08e9fd78ba1b9e95141181c69cc51795c9888157; version=99624bdff8670795b678eafa6509aaad3a5c0175 <c50729c68aaf93611c855752b00e49ce1fdd1558

Published CVSS scores

8.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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.

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.

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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