Vulnerability in grpc (CVE-2026-48599)
Summary
Vulnerability in grpc (CVE-2026-48599). Risk of unauthorized operations or information disclosure. Exploitable via GET /users/{user_id}/profile. Mitigation: upgrade to 1.0.0 or later.
Original description
The description as published by the source.
Summary
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.
Configurations
HTTP-to-gRPC transcoding must be enabled.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-48599 has been found in grpc.
Attackers can target a specific entry point like GET /users/{user_id}/profile over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade grpc to 1.0.0 or later.
If unsure, ask your IT team or search "grpc CVE-2026-48599" on the vendor's site.
CVE-2026-48599 (grpc) — CWE-639
Attack surface: GET /users/{user_id}/profile / GET /users/me/profile / grpc / user_id
Patched: 1.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-639) exists in grpc. Attackers reach the vulnerable code path via GET /users/{user_id}/profile.
Check the vendor advisory for the affected versions of grpc. Attack surface: GET /users/{user_id}/profile / GET /users/me/profile / grpc / user_id.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 1.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual GET /users/{user_id}/profile requests with malformed payloads or SQL meta-characters. Run grep -r 'grpc' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'grpc' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
grpcを grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'GET /users/{user_id}/profile' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
GET /users/{user_id}/profileへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade grpc to 1.0.0ステージング環境で 1.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against GET /users/{user_id}/profile on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- package hex.pm
- patch github.com
- web cna.erlef.org
- web osv.dev
- web github.com
- web github.com
- web github.com
- web github.com