CVE-2025-40121

Out-of-bounds access via unchecked quirk map index

Published Nov 12, 2025 · Updated May 11, 2026

Out-of-bounds access in affected Linux kernel releases allows local users to disrupt ASoC initialization through an invalid quirk option. The bytcr_rt5651 probe left the quirk input-map bits unchecked, then used that value to index the mic_name array while forming card names. Triggering requires administrative control of the driver module option and compatible Intel Bay Trail CR hardware with an RT5651 codec.

CVSS severityUnavailable
Unscored
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds access in affected Linux kernel releases allows local users to disrupt ASoC initialization through an invalid quirk option. The bytcr_rt5651 probe left the quirk input-map bits unchecked, then used that value to index the mic_name array while forming card names. Triggering requires administrative control of the driver module option and compatible Intel Bay Trail CR hardware with an RT5651 codec.

The record

CVE
CVE-2025-40121
Published
Nov 12, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Nov 12, 2025CVE 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=4.18
  2. Affected versionversion=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <2204e582b4eea872e1e7a5c90edcb84b928c68b0
  3. Affected versionversion=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <4336efb59ef364e691ef829a73d9dbd4d5ed7c7b
  4. Affected versionversion=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <64a36a7032082b4c330ce081acb6efb99246020e
  5. Affected versionversion=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <95e29db33b5f73218ae08ebb48c61c9a8d28e2ff
  6. Affected versionversion=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <bff827b0d507e52b23efab9f67c232a4f037ab2c
  7. Affected versionversion=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <c60f269c123210a6846d6d1367de0eaa402c10b0
  8. Affected versionversion=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <f197894de2f4ef46c7d53827d9df294b75c35e13
  9. Affected versionversion=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <fdf99978a6480e14405212472b6c747e0fa43bed

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=4.18; version=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <2204e582b4eea872e1e7a5c90edcb84b928c68b0; version=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <4336efb59ef364e691ef829a73d9dbd4d5ed7c7b; version=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <64a36a7032082b4c330ce081acb6efb99246020e; version=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <95e29db33b5f73218ae08ebb48c61c9a8d28e2ff; version=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <bff827b0d507e52b23efab9f67c232a4f037ab2c; version=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <c60f269c123210a6846d6d1367de0eaa402c10b0; version=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <f197894de2f4ef46c7d53827d9df294b75c35e13; version=64484ccee7af53f08cca2ee3853cb8e18914d8b2 <fdf99978a6480e14405212472b6c747e0fa43bed

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
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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