FKIE_CVE-2026-42171

Vulnerability from fkie_nvd - Published: 2026-04-24 22:16 - Updated: 2026-04-24 22:16
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Summary
NSIS (Nullsoft Scriptable Install System) 3.06.1 before 3.12 sometimes uses the Low IL temp directory when executing as SYSTEM, allowing local attackers to gain privileges (if they can cause my_GetTempFileName to return 0, as shown in the references).
References
cve@mitre.orghttps://github.com/NSIS-Dev/nsis/blob/7359413009afd4f0fff472d841fc2f2cc0e0a5f8/Source/exehead/util.c#L475-L484
cve@mitre.orghttps://github.com/NSIS-Dev/nsis/commit/8e6f02205d5f22da6c7855dbfe59b2af667330ca
cve@mitre.orghttps://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-gettempfilename
cve@mitre.orghttps://nsis.sourceforge.io/Docs/AppendixF.html#v3.12-cl
Impacted products
Vendor Product Version
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "NSIS (Nullsoft Scriptable Install System) 3.06.1 before 3.12 sometimes uses the Low IL temp directory when executing as SYSTEM, allowing local attackers to gain privileges (if they can cause my_GetTempFileName to return 0, as shown in the references)."
    }
  ],
  "id": "CVE-2026-42171",
  "lastModified": "2026-04-24T22:16:01.540",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "cve@mitre.org",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-04-24T22:16:01.540",
  "references": [
    {
      "source": "cve@mitre.org",
      "url": "https://github.com/NSIS-Dev/nsis/blob/7359413009afd4f0fff472d841fc2f2cc0e0a5f8/Source/exehead/util.c#L475-L484"
    },
    {
      "source": "cve@mitre.org",
      "url": "https://github.com/NSIS-Dev/nsis/commit/8e6f02205d5f22da6c7855dbfe59b2af667330ca"
    },
    {
      "source": "cve@mitre.org",
      "url": "https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-gettempfilename"
    },
    {
      "source": "cve@mitre.org",
      "url": "https://nsis.sourceforge.io/Docs/AppendixF.html#v3.12-cl"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-427"
        }
      ],
      "source": "cve@mitre.org",
      "type": "Primary"
    }
  ]
}


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