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CVE-2026-27826 is a server-side request forgery vulnerability in MCP Atlassian, a Model Context Protocol server for Atlassian products including Confluence and Jira. In versions prior to 0.17.0, an unauthenticated attacker who can reach the HTTP endpoint can cause the server process to issue outbound HTTP requests to an arbitrary attacker-controlled destination by supplying two custom Atlassian URL headers while omitting an Authorization header. The flaw resides in the HTTP middleware and dependency injection layer rather than in individual MCP tool handlers, which makes it less visible to tool-level code review and analysis. Because the server uses attacker-influenced upstream URL values without proper validation, the issue can be abused to reach internal services, cloud metadata endpoints, or other unintended network targets, and to inject attacker-controlled response content into downstream LLM tool results.
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No valid public exploits. Mallory filtered out 1 candidate as fakes, detection scripts, or README-only repos.
All candidate exploits were filtered out by Mallory's validation.
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Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
13 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An SSRF vulnerability in mcp-atlassian caused by unvalidated X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url headers, enabling redirection of outbound requests to attacker-controlled infrastructure and forming part of an unauthenticated SSRF-to-RCE chain.
An SSRF vulnerability referred to as CVE-2026-27826 in mcp-atlassian.
One of two vulnerabilities in the Atlassian MCP server that can be chained to achieve unauthenticated remote code execution from the local network.
An unauthenticated server-side request forgery (SSRF) in MCP Atlassian’s HTTP middleware/dependency injection layer that allows forcing outbound HTTP requests to attacker-controlled URLs, enabling internal network reconnaissance and potential cloud instance metadata/IAM credential theft.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.