CVE-2026-77248
CVE-2026-77248
8.6
HighPublished:
Last updated:
Source:security-advisories@github.com
Analyzed
CVSS Vector
v3.1- Attack Vector
- Network
- Attack Complexity
- Low
- Privileges Required
- None
- User Interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Description
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the streamable HTTP transport accepts requests without a user identity and falls back to operator credentials, while upload_attachment accepts an unrestricted file_path. An unauthenticated network caller can read files available to the MCP process, upload them to an attacker-selected Jira issue or Confluence page, and retrieve the contents. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, upload_attachment, file_path, and _get_fetcher, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
References
security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/pull/1448security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0security-advisories@github.com
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-cc5h-2pwp-pvcc134c704f-9b21-4f2e-91b3-4a467353bcc0
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-cc5h-2pwp-pvcc