Raw vector
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HSummary
CVE-2026-27825 is a critical-severity Path Traversal (CWE-22) vulnerability in Mcp-Atlassian Mcp Atlassian. Its CVSS base score is 9.0 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked in the top 19% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-27825 is a path traversal vulnerability (CWE-22, CWE-73) in the MCP Atlassian server, a Model Context Protocol (MCP) implementation for Atlassian products including Confluence and Jira. In versions prior to 0.17.0, the `confluence_download_attachment` MCP tool accepts a `download_path` parameter without directory boundary enforcement, allowing arbitrary file writes to paths accessible by the server process. This flaw enables attackers to overwrite files with content sourced from a Confluence attachment, potentially leading to arbitrary code execution. The vulnerability carries a CVSS v3.1 base score of 9.0 (AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).
An attacker with low privileges (PR:L) and adjacent network access (AV:A) can exploit this by calling the vulnerable MCP tool and providing a malicious `download_path` along with a Confluence attachment containing attacker-controlled content. Successful exploitation allows writing arbitrary data to any server-writable location, such as creating a cron job in `/etc/cron.d/` to achieve remote code execution within one scheduler cycle without requiring a server restart. No user interaction is needed (UI:N), and the scoped impact (S:C) amplifies confidentiality, integrity, and availability effects.
The issue is fixed in MCP Atlassian version 0.17.0. Security practitioners should upgrade to this version immediately. Relevant advisories and patch details are available in the GitHub security advisory at https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-xjgw-4wvw-rgm4 and the fixing commit at https://github.com/sooperset/mcp-atlassian/commit/52b9b0997681e87244b20d58034deae89c91631e.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10810
Vulnerability Data
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…
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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.
- CWE(s)
AI Security AnalysisAI
- AI Category
- AI Agent Protocols and Integrations
- Risk Domain
- Protocol-Specific Risks
- OWASP Top 10 for LLMs 2025
- None mapped
- Classification Reason
- Matched keywords: mcp, model context protocol
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Input validation directly neutralizes special path elements before pathname construction occurs.
Least privilege reduces the impact of any unauthorized file access obtained via traversal.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices include input validation and path sanitization that eliminate this weakness.
Least-privilege file authorization directly limits damage from externally controlled paths.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches path traversal via static/dynamic analysis.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Information access restriction limits which files an application may read or write.