VulnerabilityPublished 25 Sep 2026Updated 21 Oct 2026

CVE-2026-97558: Linux kernel · smb: client: fix cifsFileInfo reference leak in deferred close

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in ea93759d6c2789924f4e557aed5be532207715ea : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in ea93759d6c2789924f4e557aed5be532207715ea, bbeb7a42c9ea656e17ddcbdc2d7917aa853383a6, a6767712902beb0f53238be485971c9a83ea1079 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ c3f207ab29f793b8c942ce8067ed123f18d5b81b, < ea93759d6c2789924f4e557aed5be532207715ea	Fixed in ea93759d6c2789924f4e557aed5be532207715ea
LinuxLinux	Affected ≥ c3f207ab29f793b8c942ce8067ed123f18d5b81b, < bbeb7a42c9ea656e17ddcbdc2d7917aa853383a6	Fixed in bbeb7a42c9ea656e17ddcbdc2d7917aa853383a6
LinuxLinux	Affected ≥ c3f207ab29f793b8c942ce8067ed123f18d5b81b, < a6767712902beb0f53238be485971c9a83ea1079	Fixed in a6767712902beb0f53238be485971c9a83ea1079
LinuxLinux	Affected ≥ c3f207ab29f793b8c942ce8067ed123f18d5b81b, < 5520e89a5a4f834bced64cf2ac927001cc513a40	Fixed in 5520e89a5a4f834bced64cf2ac927001cc513a40
LinuxLinux	Affected ≥ c3f207ab29f793b8c942ce8067ed123f18d5b81b, < 525c225e23d61694091f2806de553a69362a78ff	Fixed in 525c225e23d61694091f2806de553a69362a78ff
LinuxLinux	Affected =5.13	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix cifsFileInfo reference leak in deferred close When cifs_close() defers a close, it hands the cifsFileInfo reference of the closing struct file to the queued work. Each execution of smb2_deferred_work_close() drops one such reference. deferred_close_scheduled can be false while the work is pending: the workqueue clears PENDING when the callback starts to run, before the callback clears the flag under deferred_lock. A close in that interval requeues the running work, and the callback then clears the flag, leaving the requeued work pending with the flag down. A later cifs_open() can reuse the handle and its cifs_close() reaches the same branch: queue_delayed_work() fails because the work is still pending, but cifs_close() returns without dropping the closing file's reference. The cifsFileInfo count stays pinned and its tlink, dentry and server handle are leaked. Check the return value and hand off the reference only when work was actually queued. Otherwise, use the shared _cifsFileInfo_put(), like the mod_delayed_work() branch above: the pending execution already owns its reference. This issue was found by an in-house static analysis tool.

References

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