CVE-2026-93829Hinoki check available

cifsd thread hang via premature worker startup

Published Sep 24, 2026 · Updated Sep 24, 2026

Race condition in the Linux kernel SMB client before 6.12.111 and 6.18.53 allows local users to hang a cifsd thread during SMB mounting. cifs_get_tcp_session starts the demultiplex worker before populating tcp_ses and storing its thread pointer, allowing lockless reads of partial state. Reachability requires permission to mount an SMB share and favorable scheduling; the bounded consequence is a thread sleeping for SIGKILL and disrupted mount activity.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Oct 18, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Race condition in the Linux kernel SMB client before 6.12.111 and 6.18.53 allows local users to hang a cifsd thread during SMB mounting. cifs_get_tcp_session starts the demultiplex worker before populating tcp_ses and storing its thread pointer, allowing lockless reads of partial state. Reachability requires permission to mount an SMB share and favorable scheduling; the bounded consequence is a thread sleeping for SIGKILL and disrupted mount activity.

The record

CVE
CVE-2026-93829
Published
Sep 24, 2026
Updated
Sep 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 24, 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=0 <6.12.111
  2. Affected versionversion=0 <6.18.53
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0eee1e6cddd1d9ce14da06e0238ca8d3362dec90
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e8a5cf2ff5a13fefb228f2069e29dd7d8e37185d
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ee8f811cbac56ffb738b3a73671a9e75b0f56e99

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=0 <6.12.111; version=0 <6.18.53; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0eee1e6cddd1d9ce14da06e0238ca8d3362dec90; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e8a5cf2ff5a13fefb228f2069e29dd7d8e37185d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ee8f811cbac56ffb738b3a73671a9e75b0f56e99

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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