CVE-2026-64136CWE-362

CVE-2026-64136

Critical · published July 19, 2026

CVSS v3.1
9.8
EPSS
0%
Percentile
30.7
In the wild
Unconfirmed
What it is

In the Linux kernel, the following vulnerability has been resolved:

smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()

Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields")

refactored cifs code to change cifs_tcp_ses_lock for tc_lock around

tc_count changes.

There was missing lock around tc_count increment inside

smb2_find_smb_sess_tcon_unlocked().

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00379 · 30.7th percentile
Weakness
CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Published
2026-07-19T20:17Z
Affected products (8)
ProductVersionsFixed in
linux/linux_kernel≥ 6.6.128, < 6.6.1426.6.142
linux/linux_kernel≥ 6.12.75, < 6.12.926.12.92
linux/linux_kernel≥ 6.18.16, < 6.18.346.18.34
linux/linux_kernel≥ 6.19.6, < 7.0.117.0.11
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
References (5)
https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7 · 416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41 · 416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7df1df6f40c0720d30206aa35c0343b962350e0d · 416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a · 416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd · 416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS history
Timeline
  • 19 JUL 15:40Z
    smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()
    cvelistv5