{"id":"EEF-CVE-2026-53430","summary":"grpc gzip decompression bomb in GRPC.Compressor.Gzip.decompress/1","details":"## Summary\n\nImproper 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.\n\nThis 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.\n\n'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.\n\nThis issue affects grpc: from 0.4.0 before 1.0.0.","aliases":["CVE-2026-53430","GHSA-6ccx-9c9f-327w"],"modified":"2026-08-03T18:23:26.121300563Z","published":"2026-06-15T21:55:33.707Z","database_specific":{"capec_ids":["CAPEC-130"],"cpe_ids":["cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-409"]},"references":[{"type":"ADVISORY","url":"https://github.com/elixir-grpc/grpc/security/advisories/GHSA-6ccx-9c9f-327w"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-53430.html"},{"type":"FIX","url":"https://github.com/elixir-grpc/grpc/commit/1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc"},{"type":"PACKAGE","url":"https://hex.pm/packages/grpc"}],"affected":[{"package":{"name":"grpc","ecosystem":"Hex","purl":"pkg:hex/grpc"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.4.0"},{"fixed":"1.0.0"}]}],"versions":["0.10.0","0.10.1","0.10.2","0.11.0","0.11.1","0.11.2","0.11.3","0.11.4","0.11.5","0.5.0","0.5.0-beta","0.5.0-beta.1","0.6.0","0.7.0","0.8.0","0.8.1","0.9.0","1.0.0-rc.1"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-53430.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/elixir-grpc/grpc","events":[{"introduced":"beae6800fc8baf126f3fe7107d86a50e105275ba"},{"fixed":"1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc"}]}],"versions":["v0.11.2","v0.8.1","v0.8.0","v0.7.0","v0.6.0","v0.5.0","v0.5.0-beta.1","v0.5.0-beta","v0.4.0"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-53430.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}],"credits":[{"name":"Peter Ullrich","type":"FINDER"},{"name":"Paulo Valente","type":"REMEDIATION_DEVELOPER"}]}