Authorization bypass via path binding override in elixir-grpc/grpc HTTP transcoding
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. In '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. This issue affects grpc: from 0.8.0 before 1.0.0.
CVE-2026-48599
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-48599
grpc
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
grpc
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"cpes": [
"cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"
],
"repo": "https://github.com/elixir-grpc/grpc",
"vendor": "elixir-grpc",
"modules": [
"'Elixir.GRPC.Server.Transcode'"
],
"product": "grpc",
"versions": [
{
"status": "affected",
"version": "0.8.0",
"lessThan": "1.0.0",
"versionType": "semver"
}
],
"packageURL": "pkg:hex/grpc",
"packageName": "grpc",
"programFiles": [
"lib/grpc/server/transcode.ex"
],
"collectionURL": "https://repo.hex.pm",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "'Elixir.GRPC.Server.Transcode':map_request/5"
}
]
},
{
"cpes": [
"cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"
],
"repo": "https://github.com/elixir-grpc/grpc",
"vendor": "elixir-grpc",
"modules": [
"'Elixir.GRPC.Server.Transcode'"
],
"product": "grpc",
"versions": [
{
"status": "affected",
"version": "8aaf3d3a8c4c7b08ac65e9c6f254e0d24da1d048",
"lessThan": "33b6a095dbc91c6dee3c7b90893d7d74952e82e4",
"versionType": "git"
}
],
"packageURL": "pkg:github/elixir-grpc/grpc",
"packageName": "elixir-grpc/grpc",
"programFiles": [
"lib/grpc/server/transcode.ex"
],
"collectionURL": "https://github.com",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "'Elixir.GRPC.Server.Transcode':map_request/5"
}
]
}
]- Related CVEs
- CVE-2026-48599
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #1918 · Revision 1
- Added to Heist Feed
- Publisher date