CVE-2026-77252: MCP Atlassian: JIRA_PROJECTS_FILTER and CONFLUENCE_SPACES_FILTER can be bypassed in search tools
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, caller-supplied projectsfilter and spacesfilter arguments can replace administrator-configured allowlists, and caller-provided project or space clauses can suppress the configured restriction. A caller can search projects or spaces outside the intended boundary when the configured Atlassian credentials can access them. The advisory traces the vulnerable input and processing flow through JIRAPROJECTSFILTER, CONFLUENCESPACESFILTER, projectsfilter, spacesfilter, SearchMixin.searchissues, and SearchMixin.search, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
MCP Atlassianto a version that resolves this vulnerability.Fixed in 0.22.0
Event History
Frequently Asked Questions
Who is exposed to this issue?
Deployments of MCP Atlassian before 0.22.0 are exposed if they use JIRA_PROJECTS_FILTER or CONFLUENCE_SPACES_FILTER to limit search scope and the configured Atlassian credentials can access projects or spaces outside those allowlists.
What does an attacker need to exploit the bypass?
The attacker needs the ability to invoke the affected search tools with caller-supplied projects_filter, spaces_filter, project, or space clauses. Exploitation does not require user interaction, but it is limited to data reachable by the MCP server's configured Atlassian credentials.
Are administrator-configured project and space filters sufficient protection on affected versions?
No. Before 0.22.0, caller-supplied filter arguments can replace the administrator-configured allowlists, and caller-provided project or space clauses can suppress the configured restriction.
How can this be remediated?
Upgrade MCP Atlassian to version 0.22.0, which fixes the issue. Until then, do not rely on JIRA_PROJECTS_FILTER or CONFLUENCE_SPACES_FILTER as a security boundary, and restrict the configured Atlassian credentials so they cannot access unintended projects or spaces.