CVE-2026-62847

{
  "id": "CVE-2026-62847",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-30T21:17:13.807",
  "lastModified": "2026-10-30T21:17:13.807",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Metalama is a Roslyn-based open-source patterns and architecture toolkit for C#. Prior to 2025.1.18, 2026.0.25 and 2026.1.19, Metalama.Framework and Metalama.Tool load and execute compile-time assemblies, auxiliary executable tools and embedded helper assemblies from predictable temporary directories. On `Linux` and `macOS`, the default `Path.GetTempPath()` location is world-writable, and existing artifacts are trusted based on sentinel or `.completed` marker files rather than integrity verification. A local unprivileged user on a shared machine or CI/build agent can pre-create the deterministic directory structure and plant a malicious DLL with the matching sentinel. When a higher-privileged developer or build account subsequently builds, Metalama skips regeneration and executes the planted artifact in the compiler, IDE or MSBuild process as the building user. This permits cross-user privilege escalation, reading source and secrets, supply-chain tampering with build output, or disrupting builds. Default Windows per-user temporary directories are protected by ACLs and are not affected. Deployer-selected insecure cache locations are outside the vulnerability's scope. This issue is fixed in versions 2025.1.18, 2026.0.25 and 2026.1.19."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "metalama",
          "product": "Metalama",
          "versions": [
            {
              "version": "< 2025.1.18",
              "status": "affected"
            },
            {
              "version": ">= 2025.2.0-preview, <= 2025.2.5-rc",
              "status": "affected"
            },
            {
              "version": ">= 2026.0.0-preview, < 2026.0.25",
              "status": "affected"
            },
            {
              "version": ">= 2026.1.0-preview, < 2026.1.19",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H",
          "baseScore": 8.2,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "REQUIRED",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.5,
        "impactScore": 6.0
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-377"
        },
        {
          "lang": "en",
          "value": "CWE-427"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/metalama/Metalama/commit/09911349a916e82194b1cfaa6d0a38acad928fc9",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/metalama/Metalama/commit/92c4feecfce86d18fcb007ab6d3a1b4383326a2e",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/metalama/Metalama/pull/1650",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/metalama/Metalama/releases/tag/release/2025.1.18",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/metalama/Metalama/releases/tag/release/2026.0.25",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/metalama/Metalama/releases/tag/release/2026.1.19",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/metalama/Metalama/security/advisories/GHSA-m6wq-39m7-9xpp",
      "source": "[email protected]"
    }
  ]
}