CVE-2026-27825

CRITICAL

MCP Atlassian <0.17.0 - Path Traversal

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-27825. PoCs published by plutosecurity, romain-deperne.

AI-analyzed exploit summary This repository provides a detection script for CVE-2026-27825 and CVE-2026-27826 in mcp-atlassian, which scans for vulnerable installations but does not include exploit code. It includes technical details about the vulnerabilities but no functional exploit.

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.

Exploits (2)

nomisec SCANNER 7 stars
by plutosecurity · poc
https://github.com/plutosecurity/MCPwnfluence

This repository provides a detection script for CVE-2026-27825 and CVE-2026-27826 in mcp-atlassian, which scans for vulnerable installations but does not include exploit code. It includes technical details about the vulnerabilities but no functional exploit.

Classification
Scanner 95%
Attack Type
Info Leak
Complexity
Trivial
Reliability
Reliable
Target: mcp-atlassian < 0.17.0
No auth needed
Prerequisites: mcp-atlassian installed via pip, uv, or Docker · network access to the target system
devstral-2 · analyzed Mar 11, 2026 Full analysis →
github WORKING POC
by romain-deperne · pythonpoc
https://github.com/romain-deperne/CVE-2026-27825

This repository contains a functional exploit PoC for CVE-2026-27825, a path traversal vulnerability in `sooperset/mcp-atlassian` that allows arbitrary file reads via the `confluence_upload_attachment` tool. The PoC includes a real MCP stdio client, a mock Confluence endpoint, and a script to reproduce the vulnerability end-to-end.

Classification
Working Poc 100%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Reliable
Target: sooperset/mcp-atlassian >= 0.17.0
No auth needed
Prerequisites: Network access to the vulnerable MCP server · Ability to invoke the `confluence_upload_attachment` tool
devstral-2 · analyzed Apr 30, 2026 Full analysis →

Scores

CVSS v3 9.0
EPSS 0.0002
EPSS Percentile 6.0%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-22 CWE-73
Status published
Products (2)
mcp-atlassian/mcp_atlassian < 0.17.0
sooperset/mcp-atlassian < 0.17.0
Published Mar 10, 2026
Tracked Since Mar 11, 2026