FKIE_CVE-2026-77246

Vulnerability from fkie_nvd - Published: 2026-09-22 19:16 - Updated: 2026-09-24 16:17
Severity
7.4 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Summary
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, an HTTP transport deployment with READ_ONLY_MODE=false accepts a request without an Authorization identity and permits attacker-controlled Atlassian service headers, including X-Atlassian-Confluence-Url, to select a public attacker hostname or one allowed by MCP_ALLOWED_URL_DOMAINS. A caller can then invoke confluence_upload_attachment or the Jira attachment variant in src/mcp_atlassian/jira/attachments.py with a server-local file_path and cause the MCP process to send the file to the selected attachment endpoint. This issue is fixed in version 0.22.0.
References
security-advisories@github.comhttps://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
security-advisories@github.comhttps://github.com/sooperset/mcp-atlassian/pull/1448
security-advisories@github.comhttps://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0
security-advisories@github.comhttps://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "mcp-atlassian",
          "vendor": "sooperset",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.22.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, an HTTP transport deployment with READ_ONLY_MODE=false accepts a request without an Authorization identity and permits attacker-controlled Atlassian service headers, including X-Atlassian-Confluence-Url, to select a public attacker hostname or one allowed by MCP_ALLOWED_URL_DOMAINS. A caller can then invoke confluence_upload_attachment or the Jira attachment variant in src/mcp_atlassian/jira/attachments.py with a server-local file_path and cause the MCP process to send the file to the selected attachment endpoint. This issue is fixed in version 0.22.0."
    }
  ],
  "id": "CVE-2026-77246",
  "lastModified": "2026-09-24T16:17:10.677",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-77246",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-24T15:26:25.494462Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-22T19:16:48.730",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/sooperset/mcp-atlassian/pull/1448"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        },
        {
          "lang": "en",
          "value": "CWE-200"
        },
        {
          "lang": "en",
          "value": "CWE-441"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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