Deserialization of Untrusted Data Affecting grpc_server package, versions <1.0.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-HEX-GRPCSERVER-17344409
- published16 Jun 2026
- disclosed15 Jun 2026
- creditPeter Ullrich
Introduced: 15 Jun 2026
NewCVE-2026-48853 (opens in a new tab)How to fix?
Upgrade grpc_server to version 1.0.0 or higher.
Overview
grpc_server is a GRPC is a fully featured Elixir implementation of the gRPC protocol (grpc.io), enabling efficient communication between services through a unified and stream-oriented API. It supports all RPC types, friendly error handling, TLS, interceptors, reflection, and optional HTTP transcoding.
Affected versions of this package are vulnerable to Deserialization of Untrusted Data via the decode function in Elixir.GRPC.Codec.Erlpack, which calls :erlang.binary_to_term/1 on untrusted input without the :safe option, size bounds, or type guards. An attacker can exhaust system resources or potentially cause the server to execute arbitrary code by sending crafted gRPC requests with maliciously encoded Erlang terms.
Note:
Any server that explicitly registers
GRPC.Codec.Erlpackis vulnerable to unauthenticated node-level DoS and potentially RCE.The RCE is only exploitable if the decoded value reaches any call site that applies it (e.g.
Enum.map,Task.async, direct invocation).
Details
Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.
Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.