sooperset mcp-atlassian up to 0.16.x server-side request forgery

Summaryinfo

A vulnerability was found in sooperset mcp-atlassian up to 0.16.x. It has been rated as critical. This vulnerability affects unknown code. Performing a manipulation results in server-side request forgery. This vulnerability was named CVE-2026-27826. The attack needs to be approached within the local network. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in sooperset mcp-atlassian up to 0.16.x. It has been classified as critical. This affects an unknown function. The manipulation with an unknown input leads to a server-side request forgery vulnerability. CWE is classifying the issue as CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to version 0.17.0, an unauthenticated attacker who can reach the mcp-atlassian HTTP endpoint can force the server process to make outbound HTTP requests to an arbitrary attacker-controlled URL by supplying two custom HTTP headers without an `Authorization` header. No authentication is required. The vulnerability exists in the HTTP middleware and dependency injection layer — not in any MCP tool handler - making it invisible to tool-level code analysis. In cloud deployments, this could enable theft of IAM role credentials via the instance metadata endpoint (`169[.]254[.]169[.]254`). In any HTTP deployment it enables internal network reconnaissance and injection of attacker-controlled content into LLM tool results. Version 0.17.0 fixes the issue.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-27826 since 02/24/2026. The exploitability is told to be easy. The attack needs to approached within the local network. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 0.17.0 eliminates this vulnerability.

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Productinfo

Type

• Artificial Intelligence Software

Vendor

• sooperset

Name

• mcp-atlassian

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16

Website

• Product: https://github.com/sooperset/mcp-atlassian/

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