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CVE-2026-77255

CVE-2026-77255 · MCP Atlassian: Arbitrary File Read & Exfiltration (Confused Deputy) in JIRA update_issue

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 8.6 · High · EPSS 0.5% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • mcp-atlassian

    Versions
    • < 0.22.0: Affected

    No fix published

  • mcp-atlassian PyPI

    Versions
    • 0.1.1
    • 0.1.10
    • 0.1.11
    • 0.1.12
    • 0.1.13
    • 0.1.14
    • 0.1.15
    • 0.1.16
    • 0.1.2
    • 0.1.3
    • 0.1.4
    • 0.1.6
    • 0.1.7
    • 0.1.8
    • 0.1.9
    • 0.10.0
    • 0.10.1
    • 0.10.2
    • 0.10.3
    • 0.10.4
    • 0.10.5
    • 0.10.6
    • 0.11.0
    • 0.11.1
    • 0.11.10
    • 0.11.11
    • 0.11.12
    • 0.11.2
    • 0.11.2a2
    • 0.11.3
    • 0.11.4
    • 0.11.5
    • 0.11.6
    • 0.11.7
    • 0.11.8
    • 0.11.9
    • 0.12.0
    • 0.13.0
    • 0.13.1
    • 0.14.0
    • 0.14.1
    • 0.14.2
    • 0.14.3
    • 0.15.0
    • 0.16.0
    • 0.16.1
    • 0.17.0
    • 0.18.0
    • 0.18.1
    • 0.19.0
    • 0.2.0
    • 0.2.1
    • 0.2.2
    • 0.2.3
    • 0.2.4
    • 0.2.5
    • 0.2.6
    • 0.20.0
    • 0.20.1
    • 0.21.0
    • 0.21.1
    • 0.3.0
    • 0.3.1
    • 0.4.0
    • 0.5.0
    • 0.6.0
    • 0.6.1
    • 0.6.2
    • 0.6.3
    • 0.6.4
    • 0.6.5
    • 0.7.0
    • 0.7.1
    • 0.8.0
    • 0.8.1
    • 0.8.2
    • 0.8.3
    • 0.8.4
    • 0.9.0
    Affected ranges
    • ECOSYSTEM: < 0.22.0

    Update to 0.22.0

Original sources

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