Critical 9.8Published Jul 25, 2026

CVE-2026-64383smb: client: fix double-free in SMB2_flush() replay

Updated under an hour ago (2026-10-19 08:23 UTC)

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Exploited in the last 30 days

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: 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Oct 16, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	433042a91f9373241307725b52de573933ffedbf builds before 6e27f40b682a5e42a2daae3ce6d96f0e0e16dedb; from 4f1fffa2376922f3d1d506e49c0fd445b023a28e before 878757163eea684750107a31ea134c103863515d; from 4f1fffa2376922f3d1d506e49c0fd445b023a28e before 3407240cde132a4b72d6429a2625a09a2f78adaf; from 4f1fffa2376922f3d1d506e49c0fd445b023a28e before 013a9a3da46c5dabcf18f65ea6a47874ba12a15d; 4f1fffa2376922f3d1d506e49c0fd445b023a28e builds before 4be31c943a3a27a5a0251dbb8f5cb89059ec3d5a; from 6.6.32 before 6.6.145	CNA record
linux linux_kernel linux:linux_kernel	from 6.6.32 before 6.6.145; from 6.8.1 before 6.12.96; from 6.13 before 6.18.39; from 6.19 before 7.1.4; 6.8; 6.8; 6.8; 6.8; and 3 more ranges	NVD

References

https://git.kernel.org/stable/c/6e27f40b682a5e42a2daae3ce6d96f0e0e16dedbpatch
https://git.kernel.org/stable/c/878757163eea684750107a31ea134c103863515dpatch
https://git.kernel.org/stable/c/3407240cde132a4b72d6429a2625a09a2f78adafpatch
https://git.kernel.org/stable/c/013a9a3da46c5dabcf18f65ea6a47874ba12a15dpatch
https://git.kernel.org/stable/c/4be31c943a3a27a5a0251dbb8f5cb89059ec3d5apatch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.