CVE-2026-43484

Service interruption via concurrent MMC flag updates

Published May 13, 2026 · Updated May 13, 2026

Race condition in the MMC core of affected Linux Kernel branches allows local users to interrupt service through concurrent host-state updates. The claimed flag shares a bitfield word with retune flags, so writes in __mmc_claim_host() and mmc_mq_queue_rq() overwrite unrelated state during asynchronous updates. The race requires low-privileged local access and concurrent MMC activity; the documented outcome is a spurious kernel warning, with no reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the MMC core of affected Linux Kernel branches allows local users to interrupt service through concurrent host-state updates. The claimed flag shares a bitfield word with retune flags, so writes in __mmc_claim_host() and mmc_mq_queue_rq() overwrite unrelated state during asynchronous updates. The race requires low-privileged local access and concurrent MMC activity; the documented outcome is a spurious kernel warning, with no reported data disclosure or modification.

The record

CVE
CVE-2026-43484
Published
May 13, 2026
Updated
May 13, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 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=4.15
  2. Affected versionversion=6c0cedd1ef9527ef13e66875746570e76a3188a7 <0e06cc511c61cff1591e5435a207759adcc76b6d
  3. Affected versionversion=6c0cedd1ef9527ef13e66875746570e76a3188a7 <270277c2ab631044867adb1bd2f2433d3892de6e
  4. Affected versionversion=6c0cedd1ef9527ef13e66875746570e76a3188a7 <41dce4dae583a8ce06a7ebf4ce704c46a142957c
  5. Affected versionversion=6c0cedd1ef9527ef13e66875746570e76a3188a7 <45038e03f15e992c48603fff8c6b1c9be5397ac9
  6. Affected versionversion=6c0cedd1ef9527ef13e66875746570e76a3188a7 <901084c51a0a8fb42a3f37d2e9c62083c495f824
  7. Affected versionversion=6c0cedd1ef9527ef13e66875746570e76a3188a7 <bb7fc2498c3bb25fa6a91f22f4760005325cfbd5
  8. Affected versionversion=6c0cedd1ef9527ef13e66875746570e76a3188a7 <d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.15; version=6c0cedd1ef9527ef13e66875746570e76a3188a7 <0e06cc511c61cff1591e5435a207759adcc76b6d; version=6c0cedd1ef9527ef13e66875746570e76a3188a7 <270277c2ab631044867adb1bd2f2433d3892de6e; version=6c0cedd1ef9527ef13e66875746570e76a3188a7 <41dce4dae583a8ce06a7ebf4ce704c46a142957c; version=6c0cedd1ef9527ef13e66875746570e76a3188a7 <45038e03f15e992c48603fff8c6b1c9be5397ac9; version=6c0cedd1ef9527ef13e66875746570e76a3188a7 <901084c51a0a8fb42a3f37d2e9c62083c495f824; version=6c0cedd1ef9527ef13e66875746570e76a3188a7 <bb7fc2498c3bb25fa6a91f22f4760005325cfbd5; version=6c0cedd1ef9527ef13e66875746570e76a3188a7 <d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc

Published CVSS scores

5.5OracleCVSS: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

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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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