CVE-2026-64136 (GCVE-0-2026-64136)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:40 – Updated: 2026-07-20 13:43
VLAI
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: 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().
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 953953abb66e52c224057ab91e404284fefeab62 , < 7df1df6f40c0720d30206aa35c0343b962350e0d (git)
Affected: 601dd3b79769b38d30b693c40afdb2a4b7edf9d0 , < 13fb413ae22a37c69341918a6d651d19a9b0b9b7 (git)
Affected: 3969db6b22e3d90d8c5f22ac1a7fe0350a94c136 , < bf4ebdb19ff9b3cdf992b50715fe61633327416a (git)
Affected: 96c4af418586ee9a6aab61738644366426e05316 , < e374f4e496fef8168784f93a4477d67be34485fd (git)
Affected: 96c4af418586ee9a6aab61738644366426e05316 , < 4d8690dace005a38e6dbde9ecce2da3ad85c7c41 (git)
Affected: 8c59eeeeffa1524ef57e173a89a1a3ff539888d5 (git)
Affected: 6.6.128 , < 6.6.142 (semver)
Affected: 6.12.75 , < 6.12.92 (semver)
Affected: 6.18.16 , < 6.18.34 (semver)
Affected: 6.19.6 , < 6.20 (semver)
Create a notification for this product.
Linux Linux Affected: 7.0
Unaffected: 0 , < 7.0 (semver)
Unaffected: 6.6.142 , ≤ 6.6.* (semver)
Unaffected: 6.12.92 , ≤ 6.12.* (semver)
Unaffected: 6.18.34 , ≤ 6.18.* (semver)
Unaffected: 7.0.11 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
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    "redhat_vex": {
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      "cve": "CVE-2026-64136",
      "id": "CVE-2026-64136",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_affected": "184",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64136.json",
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    "suse_vex": {
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      "current_release_date": "2026-07-21T12:59:02Z",
      "cve": "CVE-2026-64136",
      "id": "CVE-2026-64136",
      "initial_release_date": "2026-07-21T12:59:02Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64136",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64136.json",
      "version": "2"
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}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.