FKIE_CVE-2026-77254

Vulnerability from fkie_nvd - Published: 2026-09-22 19:16 - Updated: 2026-09-23 18:28
Severity
9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Summary
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, requests to the HTTP MCP endpoint without a per-user identity are allowed to reach tool handlers, which then use globally configured Jira or Confluence credentials. A network caller can perform operations with the operator account's permissions unless the deployment has an independent authentication boundary. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, _get_fetcher, and global credentials, which identify the affected entry points, controls, and code paths. 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-vc8m-84rp-53hx
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx
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, requests to the HTTP MCP endpoint without a per-user identity are allowed to reach tool handlers, which then use globally configured Jira or Confluence credentials. A network caller can perform operations with the operator account\u0027s permissions unless the deployment has an independent authentication boundary. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, _get_fetcher, and global credentials, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0."
    }
  ],
  "id": "CVE-2026-77254",
  "lastModified": "2026-09-23T18:28:25.093",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-77254",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-22T19:04:19.773536Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-22T19:16:49.693",
  "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-vc8m-84rp-53hx"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-306"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}



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