VulnerabilityPublished 18 Oct 2026

CVE-2026-98681: Linux kernel · smb: client: split cifsFileInfo bitfields to avoid shared-byte RMW races

Source GCVE Database

Authoritative record:CVE-2026-98681

Not known to be exploited · fixed in d9d23d115610e0342e768f6cb525d91c7b154027 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 12:55 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in d9d23d115610e0342e768f6cb525d91c7b154027, 4165641d06ef44f3a31b77a28048b6c737e885e7, 19465a9aeb664f1d710d0d22c07c31bfb7c85446 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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.

ghsa-f6j4-gqwr-mpr2

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 3bc303c254335dbd7c7012cc1760b12f1d5514d3, < d9d23d115610e0342e768f6cb525d91c7b154027	Fixed in d9d23d115610e0342e768f6cb525d91c7b154027
LinuxLinux	Affected ≥ 3bc303c254335dbd7c7012cc1760b12f1d5514d3, < 4165641d06ef44f3a31b77a28048b6c737e885e7	Fixed in 4165641d06ef44f3a31b77a28048b6c737e885e7
LinuxLinux	Affected ≥ 3bc303c254335dbd7c7012cc1760b12f1d5514d3, < 19465a9aeb664f1d710d0d22c07c31bfb7c85446	Fixed in 19465a9aeb664f1d710d0d22c07c31bfb7c85446
LinuxLinux	Affected ≥ 3bc303c254335dbd7c7012cc1760b12f1d5514d3, < 3786ee67658a2c80fef2544e7de2cd329e043cf9	Fixed in 3786ee67658a2c80fef2544e7de2cd329e043cf9
LinuxLinux	Affected ≥ 3bc303c254335dbd7c7012cc1760b12f1d5514d3, < 3b8e7928cf1928555dc05d172dd02fb0e7692ec4	Fixed in 3b8e7928cf1928555dc05d172dd02fb0e7692ec4
LinuxLinux	Affected =2.6.32	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel by converting the affected bitfields into separate boolean fields to prevent shared-byte read-modify-write races. Users should apply the official kernel updates that include this fix. No additional mitigation steps are indicated.

Description

A race condition vulnerability in the Linux kernel's SMB client was resolved by splitting certain bitfields in the cifsFileInfo structure into separate boolean fields. The issue involved multiple flags stored in the same byte being updated concurrently under different locks, causing potential race conditions due to read-modify-write operations on shared bytes.

References

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