VulnerabilityAnalyzed

CVE-2026-27825

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.

HIGH 8.0EPSS 12.7%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 12.7%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.

Description

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.

CVSS 3.1: 8.0 HIGHCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 12.71% probability · 96th percentile
CISA KEV: Not listed
Weakness: CWE-22, CWE-73
Affected: mcp-atlassian/mcp atlassian
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.