CVE-2026-27825: critical vulnerability in sooperset mcp-atlassian
MCP Atlassian has an arbitrary file write leading to arbitrary code execution via unconstrained download_path in confluence_download_attachment
Published
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.1epss 1.5%
exploitation probability
1.5%top 26% of all CVEs
observed exploitation
nono source reports it
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/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected products
sooperset · mcp-atlassianRelated CVEs — sooperset mcp-atlassian
In the same product, most dangerous first.
CVE-2026-27826HIGHMCP Atlassian has SSRF via unvalidated X-Atlassian-Jira-Url / X-Atlassian-Confluence-Url headersEPSS 1.0%CVE-2026-77254CRITICALMCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentialsEPSS 0.6%CVE-2026-77271HIGHMCP Atlassian: Incomplete path traversal fix allows intra-CWD module overwrite and RCE (bypass of CVE-2026-27825)EPSS 0.5%CVE-2026-77262HIGHMCP Atlassian: Path Traversal / Arbitrary File Read in confluence_upload_attachment MCP tool (incomplete fix of CVE-2026-27825)EPSS 0.5%CVE-2026-73496HIGHMCP Atlassian: Arbitrary server-side file read via attachment uploadEPSS 0.5%CVE-2026-73498HIGHMCP Atlassian is a Model Context Protocol (MCP): Arbitrary file read via missing path validation in confluence_upload_attachmentEPSS 0.5%