Arbitrary Code Execution in MCP Atlassian Server for Confluence and Jira
CVE-2026-27825

9.1CRITICAL

Key Information:

Vendor

Sooperset

Status
Mcp-atlassian
Vendor
CVE Published:
10 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-27825?

The MCP Atlassian server, utilized in Confluence and Jira, harbors a vulnerability that allows arbitrary code execution due to inadequate directory boundary enforcement in the confluence_download_attachment tool. Attackers can exploit this flaw by manipulating the download_path parameter, allowing them to write malicious content to system paths accessible by the server process. This can result in severe consequences, including the ability to execute arbitrary commands via trusted components, such as creating cron jobs without requiring server restarts.

Affected Version(s)

mcp-atlassian < 0.17.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-27825
Created by romain-deperne

References

https://github.com/sooperset/mcp-atlassian/security/advis...
x_refsource_CONFIRM
https://github.com/sooperset/mcp-atlassian/commit/52b9b09...
x_refsource_MISC

CVSS V3.1

Score:
9.1
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

.