CVE-2026-77255High· 8.6▾ MidnightPoC availableMCP 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 implementa…
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 47.3 · likelihood 0.1 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 23.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.5%
Last analysed / modified upstream
Exploit / PoC code exists
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.
Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Affected packages:
mcp-atlassian < 0.22.0Patched in:
mcp-atlassian 0.22.0Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-77260High· 8.3MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
CVE-2026-77258High· 7.7MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
CVE-2026-73496High· 7.7MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
CVE-2026-73498High· 7.7MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
CVE-2026-73497Medium· 6.5MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
GHSA-wm45-qh3g-v83fHigh· 7.7mcp-atlassian: Arbitrary server-side file read via attachment upload