CVE-2026-27826 - Vulnerability Analysis

Overview

MCP Atlassian < 0.17.0 contains a server-side request forgery caused by improper validation of custom HTTP headers in the HTTP middleware, letting unauthenticated attackers force outbound requests to arbitrary URLs, exploit requires access to the mcp-atlassian HTTP endpoint.

Severity & Score

Impact

Unauthenticated attackers can make the server send requests to arbitrary URLs, enabling internal network reconnaissance and potential credential theft.

Mitigation

Upgrade to version 0.17.0 or later.

References

• https://github.com/sooperset/mcp-atlassian/commit/5cd697dfce9116ef330b8dc7a91291640e0528d9
• https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-7r34-79r5-rcc9

Social Media Activity(1 post)

TheHackerWire

@thehackerwire

Mar 10, 2026

🟠 CVE-2026-27826 - High (8.2) 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 H... 🔗 https://www.thehackerwire.com/vulnerability/CVE-2026-27826/ #CVE #vulnerability #infosec #cybersecurity #security #Tenda #patchstack

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GitHub Repositories(1 repo)

• https://github.com/plutosecurity/MCPwnfluence

Related Resources

• Vulnerability Intelligence Dashboard
• Credential Scanner