FKIE_CVE-2026-48529

Vulnerability from fkie_nvd - Published: 2026-06-26 17:16 - Updated: 2026-06-27 04:17
Severity
6.0 (Medium) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
Summary
GitHub MCP Server is GitHub's official MCP Server. From 0.22.0 until 1.1.2, when running in HTTP mode with --lockdown-mode enabled, the RepoAccessCache is implemented as a process-global singleton initialized with the first authenticated user's GraphQL client. All subsequent requests from different users share this singleton and their lockdown-related GraphQL queries are executed using the first user's credentials. The singleton is never updated to reflect later users' tokens. This vulnerability is fixed in 1.1.2.
References
security-advisories@github.comhttps://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "github-mcp-server",
          "vendor": "github",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.22.0, \u003c 1.1.2"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "GitHub MCP Server is GitHub\u0027s official MCP Server. From 0.22.0 until 1.1.2, when running in HTTP mode with --lockdown-mode enabled, the RepoAccessCache is implemented as a process-global singleton initialized with the first authenticated user\u0027s GraphQL client. All subsequent requests from different users share this singleton and their lockdown-related GraphQL queries are executed using the first user\u0027s credentials. The singleton is never updated to reflect later users\u0027 tokens. This vulnerability is fixed in 1.1.2."
    }
  ],
  "id": "CVE-2026-48529",
  "lastModified": "2026-06-27T04:17:49.630",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 6.0,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-48529",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-27T02:42:44.775898Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-06-26T17:16:33.820",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-284"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}


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