FKIE_CVE-2026-43185

Vulnerability from fkie_nvd - Published: 2026-05-06 12:16 - Updated: 2026-05-11 20:52
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in smb_direct_prepare_negotiation() smb_direct_prepare_negotiation() casts an unsigned __u32 value from sp->max_recv_size and req->preferred_send_size to a signed int before computing min_t(int, ...). A maliciously provided preferred_send_size of 0x80000000 will return as smaller than max_recv_size, and then be used to set the maximum allowed alowed receive size for the next message. By sending a second message with a large value (>1420 bytes) the attacker can then achieve a heap buffer overflow. This fix replaces min_t(int, ...) with min_t(u32)
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6b4f875aac344cdd52a1f34cc70ed2f874a65757Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ceae058eb707ddd0d68f0872f9d9f23b7c30c37bPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 7.0
To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E3B207F9-B76D-4B19-8860-9E40E6B32274",
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix signededness bug in smb_direct_prepare_negotiation()\n\nsmb_direct_prepare_negotiation() casts an unsigned __u32 value\nfrom sp-\u003emax_recv_size and req-\u003epreferred_send_size to a signed\nint before computing min_t(int, ...). A maliciously provided\npreferred_send_size of 0x80000000 will return as smaller than\nmax_recv_size, and then be used to set the maximum allowed\nalowed receive size for the next message.\n\nBy sending a second message with a large value (\u003e1420 bytes)\nthe attacker can then achieve a heap buffer overflow.\n\nThis fix replaces min_t(int, ...) with min_t(u32)"
    }
  ],
  "id": "CVE-2026-43185",
  "lastModified": "2026-05-11T20:52:58.280",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
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        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
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  "published": "2026-05-06T12:16:37.187",
  "references": [
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      "tags": [
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      "url": "https://git.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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  "vulnStatus": "Analyzed",
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          "lang": "en",
          "value": "CWE-674"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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