CVE-2026-40534

Status: Awaiting AnalysisMedium (5.4)—

An improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Video API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows remote authenticated users to read or write limited files when the player is launched.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Base score: 5.4

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.27%
Percentile among all scored CVEs: 17
Score date: 10/5/2026

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.

ExploitationT1189 Drive-by Compromiseinitial access75 %
Primary impactT1059.007 JavaScriptexecution60 %
Secondary impactT1005 Data from Local Systemcollection65 %

XSS en Video API (CWE-79) permite ejecutar scripts en contexto del navegador. Usuario autenticado + interacción requerida (UI:R). Acceso a archivos limitados sugiere lectura de datos además de ejecución potencial.

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

Restrict Web-Based Content User Training Execution Prevention Behavior Prevention on Endpoint Disable or Remove Feature or Program Application Isolation and Sandboxing

Affected technologies (1)

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

Synology — Diskstation Manager^AI

CWEs

CWE-79

References

https://www.synology.com/en-global/security/advisory/Synology_SA_26_06

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-40534",
  "cveTags": [],
  "metrics": {
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        "ssvcData": {
          "id": "CVE-2026-40534",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-18T10:48:08.090841Z"
        }
      }
    ],
    "cvssMetricV31": [
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        "type": "Secondary",
        "source": "security@synology.com",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 5.4,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
          "integrityImpact": "LOW",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 2.7,
        "exploitabilityScore": 2.3
      }
    ]
  },
  "affected": [
    {
      "source": "security@synology.com",
      "affectedData": [
        {
          "vendor": "Synology",
          "product": "DiskStation Manager (DSM)",
          "versions": [
            {
              "status": "affected",
              "version": "7.3",
              "lessThan": "7.3.2-86009-2",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "7.2.2",
              "lessThan": "7.2.2-72806-7",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "7.2.1",
              "lessThan": "7.2.1-69057-10",
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            },
            {
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  "published": "2026-09-18T09:16:40.840",
  "references": [
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      "url": "https://www.synology.com/en-global/security/advisory/Synology_SA_26_06",
      "source": "security@synology.com"
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  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
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      "source": "security@synology.com",
      "description": [
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      "lang": "en",
      "value": "An improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Video API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows remote authenticated users to read or write limited files when the player is launched."
    }
  ],
  "lastModified": "2026-09-18T19:07:38.320",
  "sourceIdentifier": "security@synology.com"
}