CVE-2026-77258

HIGH 7.7

MCP Atlassian: Arbitrary file read/exfiltration via upload_attachment missing validate_safe_path()

CVSS Score

7.7

EPSS Score

0.0%

EPSS Percentile

0th

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, upload_attachment in src/mcp_atlassian/confluence/attachments.py accepts a caller-controlled file_path and opens the selected server-local file without restricting it to the workspace. A permitted Confluence MCP caller can upload the file as an attachment and disclose data readable by the server process. This issue is fixed in version 0.22.0.

CWE	CWE-22
Vendor	sooperset
Product	mcp-atlassian
Published	Sep 22, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Affected Versions

sooperset / mcp-atlassian

< 0.22.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-93xw-j965-9mx3 github.com: https://github.com/sooperset/mcp-atlassian/pull/1448 github.com: https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 github.com: https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0