CVE-2025-40211

Use-after-free via unsynchronized brightness work

Published Nov 21, 2025 · Updated Jun 16, 2026

Use-after-free in the Linux kernel 3.17 and later allows attackers to trigger invalid ACPI video memory access during device removal. The acpi_video_switch_brightness() delayed work dereferences device->brightness or device->backlight after acpi_video_dev_unregister_backlight() frees them. The race requires brightness work to remain queued while the ACPI video device is removed; published records do not establish a controllable trigger or consequence beyond the invalid access.

CVSS severityUnavailable
Unscored
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Use-after-free in the Linux kernel 3.17 and later allows attackers to trigger invalid ACPI video memory access during device removal. The acpi_video_switch_brightness() delayed work dereferences device->brightness or device->backlight after acpi_video_dev_unregister_backlight() frees them. The race requires brightness work to remain queued while the ACPI video device is removed; published records do not establish a controllable trigger or consequence beyond the invalid access.

The record

CVE
CVE-2025-40211
Published
Nov 21, 2025
Updated
Jun 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Nov 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 16, 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=3.17
  2. Affected versionversion=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <293125536ef5521328815fa7c76d5f9eb1635659
  3. Affected versionversion=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <3f803ccf5a0c043e7c8b83f6665b082401fc8bee
  4. Affected versionversion=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <4e85246ec0d019dfba86ba54d841ef6694f97149
  5. Affected versionversion=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <8f067aa59430266386b83c18b983ca583faa6a11
  6. Affected versionversion=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <a63a5b6fb508d78fe57ae3b159d9ef3af7ba80e9
  7. Affected versionversion=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <ba1704316492a0496c69334338ea1fdbf4c2fd34
  8. Affected versionversion=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <bc78a4f51d548c1ccc3d1967c2b394bf687c86e9
  9. Affected versionversion=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <de5fc93275a4a459fe2f7cb746984f2ab3e8292a

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=3.17; version=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <293125536ef5521328815fa7c76d5f9eb1635659; version=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <3f803ccf5a0c043e7c8b83f6665b082401fc8bee; version=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <4e85246ec0d019dfba86ba54d841ef6694f97149; version=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <8f067aa59430266386b83c18b983ca583faa6a11; version=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <a63a5b6fb508d78fe57ae3b159d9ef3af7ba80e9; version=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <ba1704316492a0496c69334338ea1fdbf4c2fd34; version=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <bc78a4f51d548c1ccc3d1967c2b394bf687c86e9; version=8ab58e8e7e097bae5fe39cbc67eb93a91f7134b7 <de5fc93275a4a459fe2f7cb746984f2ab3e8292a

Published CVSS scores

No CVSS assessment is available in this record.

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
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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