{"id":"CVE-2026-48599","state":"PUBLISHED","title":"Authorization bypass via path binding override in elixir-grpc/grpc HTTP transcoding","description":"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.","publishedAt":"2026-06-15T21:55:28.702Z","updatedAt":"2026-09-24T21:04:08.766Z","severity":{"score":7.6,"label":"High","version":"4.0","vector":"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","source":"EEF"},"assigner":"EEF","products":["elixir-grpc grpc"],"affected":[{"vendor":"elixir-grpc","product":"grpc","packageName":"grpc","packageURL":"pkg:hex/grpc","defaultStatus":"unaffected","versions":[{"version":"0.8.0","status":"affected","lessThan":"1.0.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"],"modules":["'Elixir.GRPC.Server.Transcode'"],"programFiles":["lib/grpc/server/transcode.ex"],"programRoutines":[{"name":"'Elixir.GRPC.Server.Transcode':map_request/5"}],"repo":"https://github.com/elixir-grpc/grpc"},{"vendor":"elixir-grpc","product":"grpc","packageName":"elixir-grpc/grpc","packageURL":"pkg:github/elixir-grpc/grpc","defaultStatus":"unaffected","versions":[{"version":"8aaf3d3a8c4c7b08ac65e9c6f254e0d24da1d048","status":"affected","lessThan":"33b6a095dbc91c6dee3c7b90893d7d74952e82e4","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"],"modules":["'Elixir.GRPC.Server.Transcode'"],"programFiles":["lib/grpc/server/transcode.ex"],"programRoutines":[{"name":"'Elixir.GRPC.Server.Transcode':map_request/5"}],"repo":"https://github.com/elixir-grpc/grpc"}],"references":["https://github.com/elixir-grpc/grpc/security/advisories/GHSA-mwr4-5g34-j5cq","https://cna.erlef.org/cves/CVE-2026-48599.html","https://osv.dev/vulnerability/EEF-CVE-2026-48599","https://github.com/elixir-grpc/grpc/commit/8aaf3d3a8c4c7b08ac65e9c6f254e0d24da1d048","https://github.com/elixir-grpc/grpc/commit/33b6a095dbc91c6dee3c7b90893d7d74952e82e4"],"weaknesses":["CWE-639"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/48xxx/CVE-2026-48599.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-48599","state":"PUBLISHED","datePublished":"2026-06-15T21:55:28.702Z","dateUpdated":"2026-09-24T21:04:08.766Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-05-22T09:36:56.834Z"},"containers":{"cna":{"title":"Authorization bypass via path binding override in elixir-grpc/grpc HTTP transcoding","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"elixir-grpc","product":"grpc","packageName":"grpc","packageURL":"pkg:hex/grpc","defaultStatus":"unaffected","versions":[{"version":"0.8.0","status":"affected","lessThan":"1.0.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"],"modules":["'Elixir.GRPC.Server.Transcode'"],"programFiles":["lib/grpc/server/transcode.ex"],"programRoutines":[{"name":"'Elixir.GRPC.Server.Transcode':map_request/5"}],"repo":"https://github.com/elixir-grpc/grpc"},{"vendor":"elixir-grpc","product":"grpc","packageName":"elixir-grpc/grpc","packageURL":"pkg:github/elixir-grpc/grpc","defaultStatus":"unaffected","versions":[{"version":"8aaf3d3a8c4c7b08ac65e9c6f254e0d24da1d048","status":"affected","lessThan":"33b6a095dbc91c6dee3c7b90893d7d74952e82e4","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"],"modules":["'Elixir.GRPC.Server.Transcode'"],"programFiles":["lib/grpc/server/transcode.ex"],"programRoutines":[{"name":"'Elixir.GRPC.Server.Transcode':map_request/5"}],"repo":"https://github.com/elixir-grpc/grpc"}],"references":[{"url":"https://github.com/elixir-grpc/grpc/security/advisories/GHSA-mwr4-5g34-j5cq","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-48599.html","name":"EEF CNA record for CVE-2026-48599","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-48599","name":"OSV record EEF-CVE-2026-48599","tags":["related"]},{"url":"https://github.com/elixir-grpc/grpc/commit/8aaf3d3a8c4c7b08ac65e9c6f254e0d24da1d048","name":"Introducing commit 8aaf3d3 in elixir-grpc/grpc","tags":["related"]},{"url":"https://github.com/elixir-grpc/grpc/commit/33b6a095dbc91c6dee3c7b90893d7d74952e82e4","name":"Fix commit 33b6a09 in elixir-grpc/grpc","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":7.6,"baseSeverity":"HIGH","privilegesRequired":"LOW","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-639","description":"CWE-639 Authorization Bypass Through User-Controlled Key","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-09-24T21:04:08.766Z"},"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>HTTP-to-gRPC transcoding must be enabled.</p>"},{"base64":false,"type":"text/markdown","value":"HTTP-to-gRPC transcoding must be enabled."}],"value":"HTTP-to-gRPC transcoding must be enabled."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*","versionEndExcluding":"1.0.0","versionStartIncluding":"0.8.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"Paulo Valente"},{"lang":"en","type":"analyst","value":"Jonatan Männchen / EEF"}],"datePublic":"2026-06-15T21:55:28.000Z","impacts":[{"capecId":"CAPEC-460","descriptions":[{"lang":"en","value":"CAPEC-460 HTTP Parameter Pollution (HPP)"}]}],"source":{"discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/elixir-grpc/grpc/security/advisories/GHSA-mwr4-5g34-j5cq","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-16T14:45:46.288762Z","id":"CVE-2026-48599","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-16T14:46:09.673Z"}}]}}}