{"schemaVersion":3,"id":"CVE-2026-21859","aliases":["GHSA-8v65-47jx-7mfr","GO-2026-4284"],"status":"published","duplicateOf":null,"title":null,"description":"Mailpit is an email testing tool and API for developers. Versions 1.28.0 and below have a Server-Side Request Forgery (SSRF) vulnerability in the /proxy endpoint, allowing attackers to make requests to internal network resources. The /proxy endpoint validates http:// and https:// schemes, but it does not block internal IP addresses, enabling attackers to access internal services and APIs. This vulnerability is limited to HTTP GET requests with minimal headers. 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