# CVE-2026-53430

## Summary

- **CVE ID:** CVE-2026-53430
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-409
- **Published:** Jun 15, 2026
- **Last Modified:** Jun 20, 2026

## Description

Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-grpc grpc (GRPC.Compressor.Gzip, GRPC.Message modules) allows a denial of service via a gzip decompression bomb.

This vulnerability is associated with program files lib/grpc/compressor/gzip.ex, lib/grpc/message.ex and program routines 'Elixir.GRPC.Compressor.Gzip':decompress/1, 'Elixir.GRPC.Message':from_data/2.

'Elixir.GRPC.Compressor.Gzip':decompress/1 calls :zlib.gunzip/1 directly on attacker-controlled bytes with no decompressed-size limit, ratio check, or incremental decoding. Because this module is the registered gzip GRPC.Compressor implementation, it is invoked automatically whenever an incoming gRPC frame carries the grpc-encoding: gzip header. :zlib.gunzip/1 allocates the entire decompressed result as a single binary, so a small highly compressible payload (for example a few kilobytes of zeros, which gzip compresses at roughly 1000:1) expands to multiple gigabytes inside a single call. The max_receive_message_length limit is enforced only against the already-decompressed message, so it provides no protection. An unauthenticated remote peer can send a single crafted frame to exhaust the BEAM node's heap and trigger an out-of-memory kill.

This issue affects grpc: from 0.4.0 before 1.0.0.

## Affected Products

- elixir-grpc — grpc (0.4.0)
- elixir-grpc — grpc (beae6800fc8baf126f3fe7107d86a50e105275ba)

## References

- [CNA](https://github.com/elixir-grpc/grpc/security/advisories/GHSA-6ccx-9c9f-327w)
- [CNA](https://cna.erlef.org/cves/CVE-2026-53430.html)
- [CNA](https://osv.dev/vulnerability/EEF-CVE-2026-53430)
- [CNA](https://github.com/elixir-grpc/grpc/commit/1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.35%
- **EPSS Percentile:** 27.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._