MSRXCVE-2026-77259
CVE-2026-77259
MCP Atlassian: Arbitrary file read via confluence_upload_attachment allows exfiltration of server credentials
CVSS 3.1 · CNA · github.com
chance of exploitation in the next 30 days (EPSS; higher than 38% of CVEs)
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, confluence_upload_attachment opens a caller-selected server-local file without checking that the resolved path remains in the workspace. A caller can upload environment files, credentials, or other readable host data to a Confluence page and retrieve it through Atlassian. The advisory traces the vulnerable input and processing flow through confluence_upload_attachment, file_path, and open(file_path, "rb"), which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Scores
Affected packages and fixed versions
| Package | Ecosystem | Fixed in |
|---|---|---|
| mcp-atlassian | PyPI | 0.22.0 |
Affected products
- mcp-atlassian mcp atlassian: < 0.22.0
Also known as: GHSA-6cr4-ccf3-x7h4, PYSEC-2026-4086
4 references (advisories, patches, write-ups)
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 · Patch
- https://github.com/sooperset/mcp-atlassian/pull/1448 · Issue Tracking, Patch
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 · Release Notes
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-6cr4-ccf3-x7h4 · Exploit, Mitigation, Vendor Advisory
Sources: NVD, CVE.org, OSV.dev, FIRST EPSS. Missing ones did not answer or have no record yet.