CVE-2026-53430
grpc gzip decompression bomb in GRPC.Compressor.Gzip.decompress/1
Weakness Type (CWE)
CWE-409 — CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)
CAPEC
Vulnerability 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
pkg:hex/grpc
| Module | Source File | Routine |
|---|---|---|
GRPC.Compressor.Gzip
|
lib/grpc/compressor/gzip.ex
|
GRPC.Compressor.Gzip.decompress/1
|
GRPC.Message
|
lib/grpc/message.ex
|
GRPC.Message.from_data/2
|
pkg:github/elixir-grpc/grpc
| Module | Source File | Routine |
|---|---|---|
GRPC.Compressor.Gzip
|
lib/grpc/compressor/gzip.ex
|
GRPC.Compressor.Gzip.decompress/1
|
GRPC.Message
|
lib/grpc/message.ex
|
GRPC.Message.from_data/2
|
| Status | Type | Version | Changes / Fixed in |
|---|---|---|---|
| affected | git ⓘ | beae6800fc
|
< 1afbab9d57
|
References
- https://github.com/elixir-grpc/grpc/security/advisories/GHSA-6ccx-9c9f-327w vendor-advisory related
- https://osv.dev/vulnerability/EEF-CVE-2026-53430 related
- https://github.com/elixir-grpc/grpc/commit/1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc patch
Credits
- Finder: Peter Ullrich
- Remediation developer: Paulo Valente
CVE record as JSON:
GET /cves/CVE-2026-53430.json
OSV record as JSON:
GET /osv/EEF-CVE-2026-53430.json