CVE-2026-42191

{
  "id": "CVE-2026-42191",
  "sourceIdentifier": "[email protected]",
  "published": "2026-05-12T20:16:41.000",
  "lastModified": "2026-10-26T18:10:00.173",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "OpenTelemetry.Exporter.OpenTelemetryProtocol is the OTLP (OpenTelemetry Protocol) exporter implementation. From 1.8.0 to 1.15.2, the OTLP disk retry feature in OpenTelemetry.Exporter.OpenTelemetryProtocol silently fell back to Path.GetTempPath() when OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk was set but OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH was not configured. The exporter stored and loaded *.blob files under fixed, signal-named subdirectories (traces, metrics, logs) beneath that shared temporary root path. On multi-user systems where the temporary directory is accessible to other local accounts, this allows an attacker to write crafted *.blob files, read *.blob files written by the application between export failures, or deposit numerous or oversized blob files, degrading retry-loop performance or consuming disk space. This vulnerability is fixed in 1.15.3."
    },
    {
      "lang": "es",
      "value": "OpenTelemetry.Exporter.OpenTelemetryProtocol es la implementación del exportador OTLP (OpenTelemetry Protocol). Desde 1.8.0 hasta 1.15.2, la característica de reintento en disco de OTLP en OpenTelemetry.Exporter.OpenTelemetryProtocol silenciosamente recurría a Path.GetTempPath() cuando se establecía OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk pero OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH no estaba configurado. El exportador almacenaba y cargaba archivos *.blob en subdirectorios fijos, con nombres de señal (trazas, métricas, registros) debajo de esa ruta raíz temporal compartida. En sistemas multiusuario donde el directorio temporal es accesible a otras cuentas locales, esto permite a un atacante escribir archivos *.blob manipulados, leer archivos *.blob escritos por la aplicación entre fallos de exportación, o depositar numerosos o sobredimensionados archivos blob, degradando el rendimiento del bucle de reintento o consumiendo espacio en disco. Esta vulnerabilidad está corregida en 1.15.3."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "open-telemetry",
          "product": "opentelemetry-dotnet",
          "versions": [
            {
              "version": ">= 1.8.0, < 1.15.3",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 5.5
      },
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-13T14:16:04.904029Z",
          "id": "CVE-2026-42191",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-379"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:opentelemetry:opentelemetry.exporter.opentelemetryprotocol:*:*:*:*:*:.net:*:*",
              "versionStartIncluding": "1.8.0",
              "versionEndExcluding": "1.15.3",
              "matchCriteriaId": "19F7C592-144A-4A5E-B4AB-AC191C96FC61"
            }
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  ],
  "references": [
    {
      "url": "https://github.com/open-telemetry/opentelemetry-dotnet/pull/7106",
      "source": "[email protected]",
      "tags": [
        "Issue Tracking",
        "Patch"
      ]
    },
    {
      "url": "https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-4625-4j76-fww9",
      "source": "[email protected]",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ]
    }
  ]
}