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CVE-2026-77255

Estado: AnalizadaAlta (8.6)—

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the Jira update_issue attachments argument is converted into local paths and routed to the attachment upload implementation without workspace validation. A caller can make the MCP server read arbitrary local files and attach them to a Jira issue, using the server as a confused deputy to exfiltrate the contents. The advisory traces the vulnerable input and processing flow through jira update_issue, attachments, upload_attachment, and file_path, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vector AV:N/PR:N/UI:N indica explotación remota sin autenticación (T1190). El servidor MCP lee archivos locales arbitrarios sin validación y los exfiltra a Jira (T1005 + T1041 exfiltración de datos).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Data Loss PreventionVulnerability ScanningPrivileged Account ManagementNetwork SegmentationNetwork Intrusion PreventionLimit Access to Resource Over Network

Tecnologías afectadas (1)

Mcp-atlassian — MCP Atlassian

CWE

Referencias

JSON original (NVD)

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