CVE-2026-27826

{"id": "CVE-2026-27826", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.2, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 4.7, "exploitabilityScore": 2.8}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.2, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 4.7, "exploitabilityScore": 2.8}]}, "published": "2026-03-10T19:17:20.670", "references": [{"url": "https://github.com/sooperset/mcp-atlassian/commit/5cd697dfce9116ef330b8dc7a91291640e0528d9", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-7r34-79r5-rcc9", "tags": ["Vendor Advisory", "Exploit"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-918"}]}], "descriptions": [{"lang": "en", "value": "MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to version 0.17.0, an unauthenticated attacker who can reach the mcp-atlassian HTTP endpoint can force the server process to make outbound HTTP requests to an arbitrary attacker-controlled URL by supplying two custom HTTP headers without an `Authorization` header. No authentication is required. The vulnerability exists in the HTTP middleware and dependency injection layer \u2014 not in any MCP tool handler - making it invisible to tool-level code analysis. In cloud deployments, this could enable theft of IAM role credentials via the instance metadata endpoint (`169[.]254[.]169[.]254`). In any HTTP deployment it enables internal network reconnaissance and injection of attacker-controlled content into LLM tool results. Version 0.17.0 fixes the issue."}, {"lang": "es", "value": "MCP Atlassian es un servidor de Model Context Protocol (MCP) para productos de Atlassian (Confluence y Jira). Antes de la versi\u00f3n 0.17.0, un atacante no autenticado que puede alcanzar el endpoint HTTP mcp-atlassian puede forzar al proceso del servidor a realizar solicitudes HTTP salientes a una URL arbitraria controlada por el atacante al proporcionar dos encabezados HTTP personalizados sin un encabezado 'Authorization'. No se requiere autenticaci\u00f3n. La vulnerabilidad existe en el middleware HTTP y la capa de inyecci\u00f3n de dependencias \u2014 no en ning\u00fan gestor de herramientas MCP - haci\u00e9ndola invisible para el an\u00e1lisis de c\u00f3digo a nivel de herramienta. En despliegues en la nube, esto podr\u00eda permitir el robo de credenciales de rol de IAM a trav\u00e9s del endpoint de metadatos de instancia ('169[.]254[.]169[.]254'). En cualquier despliegue HTTP permite el reconocimiento de red interno y la inyecci\u00f3n de contenido controlado por el atacante en los resultados de las herramientas LLM. La versi\u00f3n 0.17.0 soluciona el problema."}], "lastModified": "2026-04-13T15:01:48.520", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:sooperset:mcp_atlassian:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "33DDEA27-F2D6-4CF3-9EB4-C03CC01B631A", "versionEndExcluding": "0.17.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}