CVE-2026-62863

Full vulnerability record from the local CVENow database.

Description

MoLing is a computer-use and browser-use based MCP server. Prior to 0.5.0, when MoLing runs in SSE mode using `-l`, its `/sse` and `/message` HTTP endpoints do not authenticate requests and the `mcp-go` dependency sets `Access-Control-Allow-Origin: *`. A malicious web page can open a cross-origin `EventSource` to `/sse`, including a loopback listener, and read the `endpoint` event to obtain `sessionId`. After a victim running SSE mode visits that page, the attacker can use the disclosed `sessionId` against `/message` to send unauthorized MCP tool calls. Depending on the configured tools, those calls can read or write local files, execute commands or perform other actions. Binding only to loopback does not prevent this browser-mediated attack. This issue is fixed in version 0.5.0.

Severity

CRITICAL

CVSS score

9.6 (v3.1)

Vulnerability status

Received

Source identifier

[email protected]

Published

2026-10-30 21:17:14.547000

Last modified

2026-10-30 21:17:14.547000

View original CVE JSON

{
  "id": "CVE-2026-62863",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-30T21:17:14.547",
  "lastModified": "2026-10-30T21:17:14.547",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "MoLing is a computer-use and browser-use based MCP server. Prior to 0.5.0, when MoLing runs in SSE mode using `-l`, its `/sse` and `/message` HTTP endpoints do not authenticate requests and the `mcp-go` dependency sets `Access-Control-Allow-Origin: *`. A malicious web page can open a cross-origin `EventSource` to `/sse`, including a loopback listener, and read the `endpoint` event to obtain `sessionId`. After a victim running SSE mode visits that page, the attacker can use the disclosed `sessionId` against `/message` to send unauthorized MCP tool calls. Depending on the configured tools, those calls can read or write local files, execute commands or perform other actions. Binding only to loopback does not prevent this browser-mediated attack. This issue is fixed in version 0.5.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "gojue",
          "product": "moling",
          "versions": [
            {
              "version": "< 0.5.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L",
          "baseScore": 9.6,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 6.0
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-306"
        },
        {
          "lang": "en",
          "value": "CWE-942"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/gojue/moling/commit/ae07f704cbc88d4419fc0fbaec278090fcd0502d",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/gojue/moling/pull/48",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/gojue/moling/releases/tag/v0.5.0",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/gojue/moling/security/advisories/GHSA-qpgh-hp5g-4vwp",
      "source": "[email protected]"
    }
  ]
}