{"id":"CVE-2026-64136","title":"smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()\n\nCommit 96c4af418586 (\"cifs: Fix locking usage for tcon fields\")\nrefactored cifs code to c…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 953953abb66e52c224057ab91e404284fefeab62 < 7df1df6f40c0720d30206aa35c0343b962350e0d","Linux >= 601dd3b79769b38d30b693c40afdb2a4b7edf9d0 < 13fb413ae22a37c69341918a6d651d19a9b0b9b7","Linux >= 3969db6b22e3d90d8c5f22ac1a7fe0350a94c136 < bf4ebdb19ff9b3cdf992b50715fe61633327416a","Linux >= 96c4af418586ee9a6aab61738644366426e05316 < e374f4e496fef8168784f93a4477d67be34485fd","Linux >= 96c4af418586ee9a6aab61738644366426e05316 < 4d8690dace005a38e6dbde9ecce2da3ad85c7c41","Linux 8c59eeeeffa1524ef57e173a89a1a3ff539888d5","Linux >= 6.6.128 < 6.6.142","Linux >= 6.12.75 < 6.12.92","Linux >= 6.18.16 < 6.18.34","Linux >= 6.19.6 < 6.20","Linux 7.0"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:36:58.919141Z"},"published":"2026-07-19","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:42:24.842Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64136","references":[{"url":"https://git.kernel.org/stable/c/7df1df6f40c0720d30206aa35c0343b962350e0d"},{"url":"https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7"},{"url":"https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a"},{"url":"https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd"},{"url":"https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41"}],"tags":["cve.org"],"epss":0.00491,"epssPercentile":0.40779,"ingestedAt":"2026-10-16T17:24:46.809Z","slug":"CVE-2026-64136","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()\n\nCommit 96c4af418586 (\"cifs: Fix locking usage for tcon fields\")\nrefactored cifs code to change cifs_tcp_ses_lock for tc_lock around\ntc_count changes.\n\nThere was missing lock around tc_count increment inside\nsmb2_find_smb_sess_tcon_unlocked().\n\n## Affected\n\n- `Linux >= 953953abb66e52c224057ab91e404284fefeab62 < 7df1df6f40c0720d30206aa35c0343b962350e0d`\n- `Linux >= 601dd3b79769b38d30b693c40afdb2a4b7edf9d0 < 13fb413ae22a37c69341918a6d651d19a9b0b9b7`\n- `Linux >= 3969db6b22e3d90d8c5f22ac1a7fe0350a94c136 < bf4ebdb19ff9b3cdf992b50715fe61633327416a`\n- `Linux >= 96c4af418586ee9a6aab61738644366426e05316 < e374f4e496fef8168784f93a4477d67be34485fd`\n- `Linux >= 96c4af418586ee9a6aab61738644366426e05316 < 4d8690dace005a38e6dbde9ecce2da3ad85c7c41`\n- `Linux 8c59eeeeffa1524ef57e173a89a1a3ff539888d5`\n- `Linux >= 6.6.128 < 6.6.142`\n- `Linux >= 6.12.75 < 6.12.92`\n- `Linux >= 6.18.16 < 6.18.34`\n- `Linux >= 6.19.6 < 6.20`\n- `Linux 7.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}