VulnerabilityPublished 13 May 2026Updated 6 Nov 2026

CVE-2026-43484: Linux kernel · mmc: core: Avoid bitfield RMW for claim/retune flags

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc : update Linux kernel when convenient.

Data as of 6 Nov 2026, 15:49 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc, bb7fc2498c3bb25fa6a91f22f4760005325cfbd5, 901084c51a0a8fb42a3f37d2e9c62083c495f824 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 6c0cedd1ef9527ef13e66875746570e76a3188a7, < d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc	Fixed in d3a3caf44c8ec26f5d63dc17c1c7242effa60ebc
LinuxLinux	Affected ≥ 6c0cedd1ef9527ef13e66875746570e76a3188a7, < bb7fc2498c3bb25fa6a91f22f4760005325cfbd5	Fixed in bb7fc2498c3bb25fa6a91f22f4760005325cfbd5
LinuxLinux	Affected ≥ 6c0cedd1ef9527ef13e66875746570e76a3188a7, < 901084c51a0a8fb42a3f37d2e9c62083c495f824	Fixed in 901084c51a0a8fb42a3f37d2e9c62083c495f824
LinuxLinux	Affected ≥ 6c0cedd1ef9527ef13e66875746570e76a3188a7, < 270277c2ab631044867adb1bd2f2433d3892de6e	Fixed in 270277c2ab631044867adb1bd2f2433d3892de6e
LinuxLinux	Affected ≥ 6c0cedd1ef9527ef13e66875746570e76a3188a7, < 45038e03f15e992c48603fff8c6b1c9be5397ac9	Fixed in 45038e03f15e992c48603fff8c6b1c9be5397ac9
LinuxLinux	Affected ≥ 6c0cedd1ef9527ef13e66875746570e76a3188a7, < 41dce4dae583a8ce06a7ebf4ce704c46a142957c	Fixed in 41dce4dae583a8ce06a7ebf4ce704c46a142957c

Description

In the Linux kernel, the following vulnerability has been resolved: mmc: core: Avoid bitfield RMW for claim/retune flags Move claimed and retune control flags out of the bitfield word to avoid unrelated RMW side effects in asynchronous contexts. The host->claimed bit shared a word with retune flags. Writes to claimed in __mmc_claim_host() or retune_now in mmc_mq_queue_rq() can overwrite other bits when concurrent updates happen in other contexts, triggering spurious WARN_ON(!host->claimed). Convert claimed, can_retune, retune_now and retune_paused to bool to remove shared-word coupling.

References

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