---
cve: "CVE-2026-48599"
severity: "HIGH"
cvss: 7.6
epss: "27%"
vendor: "elixir-grpc"
kev: false
exploited: false
published: "2026-06-15 23:16:45"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-10T23:34:20+02:00"
---

# CVE-2026-48599

> 7.6 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 8105f803030f7f5ae1d722251ee6ab2e36878830 (Commit)
- 33b6a095dbc91c6dee3c7b90893d7d74952e82e4 (Commit)

## Referenzen

- <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/33b6a095dbc91c6dee3c7b90893d7d74952e82e4>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-48599) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_