Vulnerability-Lookup

GHSA-6VVF-F9VP-VCGV

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:32

Details

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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64136"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:55Z",
    "severity": "CRITICAL"
  },
  "details": "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 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().",
  "id": "GHSA-6vvf-f9vp-vcgv",
  "modified": "2026-07-20T15:32:01Z",
  "published": "2026-07-19T18:31:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64136"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7df1df6f40c0720d30206aa35c0343b962350e0d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

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

Vulnerability from cvelistv5 – Published: 2026-07-19 15:40 – Updated: 2026-07-20 13:43

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

Linux

References

5 references

URL	Tags
https://git.kernel.org/stable/c/7df1df6f40c0720d3…
https://git.kernel.org/stable/c/13fb413ae22a37c69…
https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf…
https://git.kernel.org/stable/c/e374f4e496fef8168…
https://git.kernel.org/stable/c/4d8690dace005a38e…

Impacted products

2 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)
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)

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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/smb2transport.c"
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              "status": "unaffected",
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        }
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        "dateUpdated": "2026-07-20T13:43:41.329Z",
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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.

Action not permitted

GHSA-6VVF-F9VP-VCGV

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

Tags

Sightings

Nomenclature