Vulnerability · Published Sep 14, 2026 · Assigned by GitHub_M

CVE-2026-73496MCP Atlassian: Arbitrary server-side file read via attachment upload

High 7.7

In plain English

A high-severity path traversal in mcp-atlassian from sooperset. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.7High
Exploit odds (30 days)0.5%top 58.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the confluence_upload_attachment and confluence_upload_attachments tools pass a client-controlled file_path through src/mcp_atlassian/confluence/attachments.py upload_attachment, and the jira_update_issue attachments parameter reaches src/mcp_atlassian/jira/attachments.py upload_attachment, without confining either path to an approved server workspace. In a remote HTTP, SSE, or multi-user deployment, absolute or traversing paths are resolved on the MCP server and uploaded to Atlassian, allowing a client with write-tool access to disclose server files, environment-held Atlassian credentials, or another tenant's data. A local single-user stdio deployment does not cross this trust boundary because the server runs in the caller's environment. This issue is fixed in version 0.22.0.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
PyPImcp-atlassian0.22.0GHSA-wm45-qh3g-v83f

Affected products (as reported)

VendorProductVersions
sooperset mcp-atlassian < 0.22.0

Weakness: CWE-22, CWE-73 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

References