Path Traversal in Mcp-Atlassian Mcp Atlassian

CVE-2026-27825

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to version 0.17.0, the `confluence_download_attachment` MCP tool accepts a `download_path` parameter that is written to without any directory boundary enforcement. An attacker who can call this tool and supply or access a Confluence attachment with malicious content can write arbitrary content to any path the server process has write access to. Because the attacker controls both the write destination and the written content (via an uploaded Confluence attachment), this constitutes for arbitrary code execution (for example, writing a valid cron entry to `/etc/cron.d/` achieves code execution within one scheduler cycle with no server restart required). Version 0.17.0 fixes the issue.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.015 (73.7th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 73.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-27825: fell from 0.127 to 0.015.

EPSS over last 30 days · oldest: 0.127 · newest: 0.015 · change: -0.112

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-27825?
CVE-2026-27825 is a critical-severity vulnerability in Mcp-Atlassian Mcp Atlassian, classified under Path Traversal. CVSS score: 9.0/10. Published 2026-03-10.
How severe is CVE-2026-27825?
Critical severity. CVSS v3 base score is 9.0 out of 10.
Is CVE-2026-27825 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.