CVE-2026-77266
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, upload_attachment accepts absolute paths and traversal sequences without constraining the resolved path to the server workspace. An MCP caller with attachment access can read a chosen server-local file and exfiltrate it through Jira or Confluence. The advisory traces the vulnerable input and processing flow through upload_attachment, file_path, and path traversal, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Published:Sep 22, 2026
Last Modified:Sep 28, 2026
EPS:Sep 22, 2026
EPSS Score:0.00475
CVSS Score:6.5
Affected Products
Vendor
Product
Action
Vendor
Mcp-atlassian
Product
Mcp Atlassian
Mcp-atlassian
Mcp Atlassian
Vendor
Sooperset
Product
Mcp-atlassian
Sooperset
Mcp-atlassian
Exploits
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
References
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
