CVE-2026-73496 MCP Atlassian: Arbitrary server-side file read via attachment upload
Attackers can read arbitrary server files and credentials via path traversal in attachment upload tools in remote deployments.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-73496?
CVE-2026-73496 is a high-severity path traversal vulnerability in sooperset mcp-atlassian, published on 14 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Which versions are affected by CVE-2026-73496?
2 open source packages ship an affected version, including mcp-atlassian.
| Package | Affected | Fixed in |
|---|---|---|
mcp-atlassian PyPI | All versions | 0.22.0 |
mcp-atlassian PyPI | All versions | 0.22.0 |
How do I fix CVE-2026-73496?
Upgrade mcp-atlassian to 0.22.0 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-73496 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73496 exists.
Sources
Also known as GHSA-wm45-qh3g-v83f.