CVE-2026-86871

Status: Awaiting AnalysisMedium (5.9)—

Severity5.9Medium · CVSS 3.1

Exploitation probability0.17 %higher than 6% of CVEs

Active exploitationNonot in the CISA catalog

Public exploitNot knownno public code found

An integer underflow was addressed with improved input validation. This issue is fixed in macOS Golden Gate 27, macOS Sequoia 15.8, macOS Tahoe 26.7. An attacker with control of a network file server may be able to cause unexpected system termination.

CVSS

Base score: 5.9
Version: 3.1
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.17 %
Percentile among all scored CVEs: 6
Score date: 10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access70 %
Primary impactT1499 Endpoint Denial of Serviceimpact85 %

Vector AV:N/PR:N/UI:N indica explotación remota sin privilegios; la descripción señala terminación inesperada del sistema (A:H), lo que encaja con DoS.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Filter Network Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application Isolation and Sandboxing

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Apple — Macos^AI

CWEs

CWE-20, CWE-190

References

Show 3 references

Raw JSON (NVD)

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{
  "id": "CVE-2026-86871",
  "cveTags": [],
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          "role": "CISA Coordinator",
          "options": [
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            },
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              "automatable": "no"
            },
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          "version": "2.0.3",
          "timestamp": "2026-10-20T14:39:26.599060Z"
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          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
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        "impactScore": 3.6,
        "exploitabilityScore": 2.2
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  "affected": [
    {
      "source": "product-security@apple.com",
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  "published": "2026-10-20T01:17:25.253",
  "references": [
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      "url": "https://support.apple.com/en-us/149035",
      "source": "product-security@apple.com"
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    {
      "url": "https://support.apple.com/en-us/149042",
      "source": "product-security@apple.com"
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    {
      "url": "https://support.apple.com/en-us/149043",
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  ],
  "lastModified": "2026-10-20T15:17:33.953",
  "sourceIdentifier": "product-security@apple.com"
}