CVE-2026-64136
Vulnerability Summary
Timeline
Description
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().
CVSS Metrics
- v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Trends
Current EPSS score: 0.49%• Percentile: 41%
Affected Systems
- debian•linux
< 6.12.94-1 | < 7.0.12-1
- ubuntu•linux
all | < 6.8.0-139.139 | < 7.0.0-28.28
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
all | < 7.0.0-1009.9
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.14
all
- ubuntu•linux-aws-6.17
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-6.5
all
- ubuntu•linux-aws-6.8
all
- ubuntu•linux-aws-fips
all
- ubuntu•linux-azure
all | all | < 6.8.0-1067.75 | < 7.0.0-1010.10
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.11
all
- ubuntu•linux-azure-6.14
all
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-6.5
all
- ubuntu•linux-azure-6.8
all
- ubuntu•linux-azure-7.0
all
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all | all | < 7.0.0-1009.9
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.14
all
- ubuntu•linux-azure-fde-6.17
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-azure-fde-6.8
all
- ubuntu•linux-azure-fips
all | < 6.8.0-1067.75+fips1
- ubuntu•linux-azure-nvidia
all
- ubuntu•linux-azure-nvidia-6.14
all
- ubuntu•linux-bluefield
all | < 6.8.0-1030.35
- ubuntu•linux-fips
all | < 6.8.0-139.139+fips1
- ubuntu•linux-gcp
all | all | < 6.8.0-1067.75 | < 7.0.0-1008.8
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
- ubuntu•linux-gcp-5.19
all
- ubuntu•linux-gcp-5.3
all
- ubuntu•linux-gcp-5.8
all
- ubuntu•linux-gcp-6.11
all
- ubuntu•linux-gcp-6.14
all
- ubuntu•linux-gcp-6.2
all
- ubuntu•linux-gcp-6.5
all
Showing first 50 affected entries in server-rendered view.
References (20)
- https://git.kernel.org/stable/c/7df1df6f40c0720d30206aa35c0343b962350e0d
- https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7
- https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a
- https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd
- https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41
- https://ubuntu.com/security/CVE-2026-64136
- https://www.cve.org/CVERecord?id=CVE-2026-64136
- https://git.kernel.org/linus/4d8690dace005a38e6dbde9ecce2da3ad85c7c41
- https://ubuntu.com/security/notices/USN-8593-1
- https://ubuntu.com/security/notices/USN-8603-1
- https://ubuntu.com/security/notices/USN-8618-1
- https://security-tracker.debian.org/tracker/CVE-2026-64136
- https://ubuntu.com/security/notices/USN-8663-1
- https://ubuntu.com/security/notices/USN-8664-1
- https://ubuntu.com/security/notices/USN-8728-1
- https://ubuntu.com/security/notices/USN-8729-1
- https://ubuntu.com/security/notices/USN-8761-1
- https://ubuntu.com/security/notices/USN-8729-2
- https://ubuntu.com/security/notices/USN-8761-2
- https://ubuntu.com/security/notices/USN-8781-1