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CVE-2026-64383

Linux Kernel double free

9.8 CRITICALEPSS 0.46%
  1. Published25 Jul 2026

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time. Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Kernel≥ 6.13 < 6.18.39 · ≥ 6.19 < 7.1.4 · ≥ 6.6.32 < 6.6.145 · ≥ 6.8.1 < 6.12.96

Remediation

Fixed in
Linux Kernel≥ 6.18.39

References

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Frequently asked

Is CVE-2026-64383 being actively exploited?

CVE-2026-64383 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.46%.

How severe is CVE-2026-64383?

CVE-2026-64383 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.46% probability of exploitation.

Which products are affected by CVE-2026-64383?

Affected products include Linux Kernel.

How do I fix CVE-2026-64383?

Upgrade affected software to a fixed version, for example Linux Kernel 6.18.39 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.