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TI-2026-53952 Aliases CVE-2026-77268GHSA-4596-2p6p-28cv

MCP Atlassian: Insecure File Permissions on OAuth Token Storage

Priority LOW 24CWE-732Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the OAuth fallback token directory and JSON file are created without explicit owner-only modes. Local users or processes with access through the resulting group or world permission bits can read access and refresh tokens and reuse the associated Atlassian session. The advisory traces the vulnerable input and processing flow through ~/.mcp-atlassian, oauth-<client_id>.json, access_token, and refresh_token, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00153 4th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed mcp-atlassian (sooperset): 0.22.0mcp-atlassian (PyPI): 0.22.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
soopersetmcp-atlassianbefore 0.22.00.22.0Patch availableCNA
—mcp-atlassian (PyPI)before 0.22.00.22.0Patch availableGHSA-4596-2p6p-28cv
  • mcp-atlassian Vendorsooperset Affected before 0.22.0 Fixed in 0.22.0 Patch available CNA
  • mcp-atlassian (PyPI) Vendor— Affected before 0.22.0 Fixed in 0.22.0 Patch available GHSA-4596-2p6p-28cv

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:*before 0.22.0VulnerableMcp-atlassian
  • cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:* Versions before 0.22.0 Vulnerable ·Mcp-atlassian

Remediation

  • Fix · CNA mcp-atlassian (sooperset) Fixed in 0.22.0
  • Fix · GHSA-4596-2p6p-28cv mcp-atlassian (PyPI) Fixed in 0.22.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-77268
  2. 2026-10-03 Alias added: GHSA-4596-2p6p-28cv

References

Exploit 1

Patch 2

Other 2

  • TI-2026-53938 MCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentials CVSS 3.1CRITICAL 9.1
  • TI-2026-53957 MCP Atlassian: SSRF Protection Bypass CVSS 4.0HIGH 8.8
  • TI-2026-53935 Protection mechanism failure in sooperset mcp-atlassian CVSS 4.0HIGH 8.3
  • TI-2026-53946 Path traversal in sooperset mcp-atlassian CVSS 3.1HIGH 8.6
  • TI-2026-53932 Path traversal in sooperset mcp-atlassian CVSS 3.1HIGH 8.6
  • TI-2026-22177 Path traversal in sooperset mcp-atlassian CVSS 3.1CRITICAL 9.1
See all 33 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences