CVE-2026-77252: MCP Atlassian — MEDIUM

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, caller-supplied projects_filter and spaces_filter arguments can replace administrator-configured allowlists, and caller-provided project or space clauses can suppress the configured...

Full CISO analysis pending enrichment.

What systems are affected?

Package	Ecosystem	Vulnerable Range	Patched
MCP Atlassian	pip	—	No patch
1 dependents 33% patched ~10d to patch Full package profile →

Do you use MCP Atlassian? You're affected.

How severe is it?

CVSS 3.1

6.5 / 10

EPSS

N/A

Exploitation Status

No known exploitation

Sophistication

N/A

What is the attack surface?

AV Network

AC Low

PR Low

UI None

S Unchanged

C High

I None

A None

What should I do?

No patch available

Monitor for updates. Consider compensating controls or temporary mitigations.

Which compliance frameworks are affected?

Compliance analysis pending. Sign in for full compliance mapping when available.

Frequently Asked Questions

What is CVE-2026-77252?

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, caller-supplied projects_filter and spaces_filter 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 JIRA_PROJECTS_FILTER, CONFLUENCE_SPACES_FILTER, projects_filter, spaces_filter, SearchMixin.search_issues, and SearchMixin.search, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Is CVE-2026-77252 actively exploited?

No confirmed active exploitation of CVE-2026-77252 has been reported, but organizations should still patch proactively.

How to fix CVE-2026-77252?

No patch is currently available. Monitor vendor advisories for updates.

What is the CVSS score for CVE-2026-77252?

CVE-2026-77252 has a CVSS v3.1 base score of 6.5 (MEDIUM).

What are the technical details?

Original Advisory

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, caller-supplied projects_filter and spaces_filter 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 JIRA_PROJECTS_FILTER, CONFLUENCE_SPACES_FILTER, projects_filter, spaces_filter, SearchMixin.search_issues, and SearchMixin.search, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Weaknesses (CWE)

CWE-284 Improper Access Control

CWE-284 — Improper Access Control: The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

[Architecture and Design, Operation] Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
[Architecture and Design] Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Source: MITRE CWE corpus.