MCP Atlassian: SSRF via DNS Rebinding in Header-Based Authentication Flow

SummaryThe SSRF protection for header-based authentication uses a validate-then-use pattern vulnerable to DNS rebinding. validateurlforssrf resolves the hostname via DNS and checks that the resolved IP is globally routable. However, the actual HTTP request happens later, during which the DNS reco...

PYSEC-2026-4083 MCP Atlassian: SSRF via DNS Rebinding in Header-Based Authentication Flow

Summary The SSRF protection for header-based authentication uses a validate-then-use pattern vulnerable to DNS rebinding. validateurlforssrf resolves the hostname via DNS and checks that the resolved IP is globally routable. However, the actual HTTP request happens later, during which the DNS...

MCP Atlassian: SSRF Protection Bypass

Environment - Project: sooperset/mcp-atlassian - Affected function: validateurlforssrf - Affected path: header-based Jira/Confluence URL authentication flow - Tested endpoint: POST /mcp - Tested version: 2.14.5 Description The SSRF protection in validateurlforssrf can be bypassed with a URL...

GHSA-49XV-9743-PW8W MCP Atlassian: SSRF via DNS Rebinding in Header-Based Authentication Flow

Summary The SSRF protection for header-based authentication uses a validate-then-use pattern vulnerable to DNS rebinding. validateurlforssrf resolves the hostname via DNS and checks that the resolved IP is globally routable. However, the actual HTTP request happens later, during which the DNS...