{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-53430: grpc gzip decompression bomb in GRPC.Compressor.Gzip.decompress/1","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-53430","status":"final","version":"1","initial_release_date":"2026-06-15T21:55:33.707Z","current_release_date":"2026-06-15T21:55:33.707Z","revision_history":[{"date":"2026-06-15T21:55:33.707Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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.\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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-53430 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-53430"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-53430"},{"category":"external","summary":"github.com","url":"https://github.com/elixir-grpc/grpc/security/advisories/GHSA-6ccx-9c9f-327w"},{"category":"external","summary":"cna.erlef.org","url":"https://cna.erlef.org/cves/CVE-2026-53430.html"},{"category":"external","summary":"osv.dev","url":"https://osv.dev/vulnerability/EEF-CVE-2026-53430"},{"category":"external","summary":"github.com","url":"https://github.com/elixir-grpc/grpc/commit/1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc"}]},"product_tree":{"branches":[{"category":"vendor","name":"elixir-grpc","branches":[{"category":"product_name","name":"grpc","branches":[{"category":"product_version_range","name":">=0.4.0 <1.0.0","product":{"name":"elixir-grpc grpc >=0.4.0 <1.0.0","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"}}}]}]},{"category":"vendor","name":"elixir-grpc","branches":[{"category":"product_name","name":"grpc","branches":[{"category":"product_version_range","name":">=beae6800fc8baf126f3fe7107d86a50e105275ba <1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc","product":{"name":"elixir-grpc grpc >=beae6800fc8baf126f3fe7107d86a50e105275ba <1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-53430","title":"grpc gzip decompression bomb in GRPC.Compressor.Gzip.decompress/1","notes":[{"category":"description","text":"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.\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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1","CSAFPID-2"]},"scores":[{"cvss_v4":{"version":"4.0","vectorString":"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","baseScore":8.7,"baseSeverity":"HIGH"},"products":["CSAFPID-1","CSAFPID-2"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 1.0.0, 1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc.","product_ids":["CSAFPID-1","CSAFPID-2"],"url":"https://github.com/elixir-grpc/grpc/commit/1afbab9d57d2a3e16ca9c62ffa4923338ea96cfc"}]}]}