CVE-2026-77266

medium

Description

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.

References

https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-mfv2-4wvm-9pgp

https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0

https://github.com/sooperset/mcp-atlassian/pull/1448

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-84747

Details

Source: Mitre, NVD

Published: 2026-09-22

Updated: 2026-09-28

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Severity: Medium

EPSS

EPSS: 0.00481