{"id":"CVE-2026-48599","summary":"Authorization bypass via path binding override in elixir-grpc/grpc HTTP transcoding","details":"Authorization Bypass Through User-Controlled Key vulnerability in elixir-grpc grpc allows authenticated attackers to access or modify resources belonging to other users by smuggling a conflicting value for any path-bound field via the query string or request body.\n\nIn 'Elixir.GRPC.Server.Transcode':map_request/5 (lib/grpc/server/transcode.ex), all three clauses use Map.merge/2 with path bindings as the first argument, giving them the lowest merge precedence. A request such as GET /users/me/profile?user_id=victim (or a POST with {\"user_id\": \"victim\"} when body: \"*\") yields a decoded protobuf struct where the path-bound field carries the attacker-supplied value rather than the router-extracted value. Any handler that uses the path-bound field for authorization, multi-tenancy scoping, or ownership checks is silently bypassed.\n\nThis issue affects grpc from 0.8.0 before 1.0.0.","aliases":["EEF-CVE-2026-48599","GHSA-mwr4-5g34-j5cq"],"modified":"2026-06-18T03:56:23.550942540Z","published":"2026-06-15T21:55:28.702Z","database_specific":{"cwe_ids":["CWE-639"],"cna_assigner":"EEF","unresolved_ranges":[{"extracted_events":[{"introduced":"8aaf3d3a8c4c7b08ac65e9c6f254e0d24da1d048"},{"fixed":"33b6a095dbc91c6dee3c7b90893d7d74952e82e4"}],"source":"AFFECTED_FIELD"}],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48599.json"},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-48599.html"},{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-48599"},{"type":"WEB","url":"https://repo.hex.pm"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48599.json"},{"type":"ADVISORY","url":"https://github.com/elixir-grpc/grpc/security/advisories/GHSA-mwr4-5g34-j5cq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48599"},{"type":"FIX","url":"https://github.com/elixir-grpc/grpc/commit/33b6a095dbc91c6dee3c7b90893d7d74952e82e4"},{"type":"PACKAGE","url":"https://github.com/elixir-grpc/grpc"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/elixir-grpc/grpc","events":[{"introduced":"eda2edc2f43010517b9f7992ccb181792175a17f"},{"fixed":"8105f803030f7f5ae1d722251ee6ab2e36878830"},{"fixed":"33b6a095dbc91c6dee3c7b90893d7d74952e82e4"}],"database_specific":{"extracted_events":[{"introduced":"0.8.0"},{"fixed":"1.0.0"}],"source":["DESCRIPTION","REFERENCES"]}}],"versions":["v0.11.2","v0.8.1","v0.8.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-48599.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"}]}