CVE-2026-77254: 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…

PriorityP263critical9.1CVSS 3.1

AVNACLPRNUINSUCHIHAN

EPSS

0.62%

48.0th percentile

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.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
mcp-atlassian	mcp_atlassian	< 0.22.0	0.22.0
sooperset	mcp-atlassian	< 0.22.0	0.22.0

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