CVE-2026-97558

Resource leak via deferred-close requeue race

Published Sep 25, 2026 · Updated Sep 25, 2026

Resource leak in the Linux kernel SMB client 5.13 allows attackers to pin file and server-handle references through deferred closes. In cifs_close(), a requeued work item can remain pending after its scheduling flag is cleared, and a failed queue_delayed_work() call returns without releasing the new cifsFileInfo reference. Triggering requires file open and close operations on a mounted SMB share during the narrow workqueue race; the leaked tlink, dentry, and server handle remain allocated.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource leak in the Linux kernel SMB client 5.13 allows attackers to pin file and server-handle references through deferred closes. In cifs_close(), a requeued work item can remain pending after its scheduling flag is cleared, and a failed queue_delayed_work() call returns without releasing the new cifsFileInfo reference. Triggering requires file open and close operations on a mounted SMB share during the narrow workqueue race; the leaked tlink, dentry, and server handle remain allocated.

The record

CVE
CVE-2026-97558
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 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=5.13
  2. Affected versionversion=c3f207ab29f793b8c942ce8067ed123f18d5b81b <5520e89a5a4f834bced64cf2ac927001cc513a40
  3. Affected versionversion=c3f207ab29f793b8c942ce8067ed123f18d5b81b <ea93759d6c2789924f4e557aed5be532207715ea

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.13; version=c3f207ab29f793b8c942ce8067ed123f18d5b81b <5520e89a5a4f834bced64cf2ac927001cc513a40; version=c3f207ab29f793b8c942ce8067ed123f18d5b81b <ea93759d6c2789924f4e557aed5be532207715ea

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)
VectorUnavailable
PrivilegesUnavailable
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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