CVE-2026-43379 (GCVE-0-2026-43379)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:21 – Updated: 2026-08-05 12:27
VLAI
Title
ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close() opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is being accessed after rcu_read_unlock() has been called. This creates a race condition where the memory could be freed by a concurrent writer between the unlock and the subsequent pointer dereferences (opinfo->is_lease, etc.), leading to a use-after-free.
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 CPE status
Linux Linux Affected: 27b40b7bfcd121fe13a150ffe11957630cf49246 , < bf4d66d72e4a9e268c1012c331ce9eaedb5e2086 (git)
Affected: 5fb282ba4fef8985a5acf2b32681f2ec07732561 , < 960699317d39f46611f4ebeb69edc567c1f4e6b6 (git)
Affected: 5fb282ba4fef8985a5acf2b32681f2ec07732561 , < dbbd328cf58261ca239756fe1c0d10c9518d3399 (git)
Affected: 5fb282ba4fef8985a5acf2b32681f2ec07732561 , < b3568347c51c46e2cabc356bc34676df98296619 (git)
Affected: 5fb282ba4fef8985a5acf2b32681f2ec07732561 , < eac3361e3d5dd8067b3258c69615888eb45e9f25 (git)
Affected: 6.6.32 , < 6.6.130 (semver)
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Linux Linux Affected: 6.9
Unaffected: 0 , < 6.9 (semver)
Unaffected: 6.6.130 , ≤ 6.6.* (semver)
Unaffected: 6.12.78 , ≤ 6.12.* (semver)
Unaffected: 6.18.19 , ≤ 6.18.* (semver)
Unaffected: 6.19.9 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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    "dateReserved": "2026-05-01T14:12:56.006Z",
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    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-28T07:37:15+00:00",
      "cve": "CVE-2026-43379",
      "id": "CVE-2026-43379",
      "initial_release_date": "2026-05-08T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43379.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-06T01:20:12Z",
      "cve": "CVE-2026-43379",
      "id": "CVE-2026-43379",
      "initial_release_date": "2026-05-12T03:30:29Z",
      "product_status:known_affected": "17",
      "product_status:known_not_affected": "278",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-43379",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-43379.json",
      "version": "5"
    }
  }
}



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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.