Allocation of Resources Without Limits or Throttling vulnerability in elixir-grpc grpc_server…

Why it is Yellow

• CVSS 8.2 high
• Remotely exploitable without logging in

References

• https://cna.erlef.org/cves/CVE-2026-71397.html
• https://github.com/elixir-grpc/grpc/commit/0b663ca53dbf0f36f7f67ff1d0026f4482a18915
• https://github.com/elixir-grpc/grpc/commit/49e18c3ec6bb9afe2f712caad3dbab5c56a68a00
• https://github.com/elixir-grpc/grpc/security/advisories/GHSA-vx6q-cr5q-945g
• https://osv.dev/vulnerability/EEF-CVE-2026-71397

Original description

Allocation of Resources Without Limits or Throttling vulnerability in elixir-grpc grpc_server allows unauthenticated attackers to exhaust memory and crash the node via an oversized client-streaming or bidirectional-streaming request body. The streaming read clause of 'Elixir.GRPC.Server.Adapters.Cowboy.Handler':info/3 (grpc_server/lib/grpc/server/adapters/cowboy/handler.ex) never checks the configured max_body_size. Only the unary read path enforces that cap. 'Elixir.GRPC.Server.Adapters.Cowboy':reading_stream/1 (grpc_server/lib/grpc/server/adapters/cowboy.ex) appends every received chunk to its buffer until a complete length-prefixed message arrives. A client can declare a very large message and send it across many small HTTP/2 DATA frames, and the server buffers all of it. This issue affects grpc_server: from 1.0.0 before 1.0.6.