{"cve":"CVE-2023-32731","nvd":{"published":"2023-06-09T11:15:09.303","modified":"2026-06-17T05:59:28.300","status":"Modified","description":"When gRPC HTTP2 stack raised a header size exceeded error, it skipped parsing the rest of the HPACK frame. This caused any HPACK table mutations to also be skipped, resulting in a desynchronization of HPACK tables between sender and receiver. If leveraged, say, between a proxy and a backend, this could lead to requests from the proxy being interpreted as containing headers from different proxy clients - leading to an information leak that can be used for privilege escalation or data exfiltration. We recommend upgrading beyond the commit contained in  https://github.com/grpc/grpc/pull/33005 https://github.com/grpc/grpc/pull/33005","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5},"cwes":["CWE-440"],"references":["https://github.com/grpc/grpc/pull/32309","https://github.com/grpc/grpc/pull/33005","https://github.com/grpc/grpc/pull/32309","https://github.com/grpc/grpc/pull/33005"],"products":["grpc:grpc"],"source":"nvd","synced_at":"2026-10-19T21:38:24.161619714+00:00"},"epss":{"cve":"CVE-2023-32731","score":0.00498,"percentile":0.42717,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-cfgp-2977-2fmm","url":"https://osv.dev/vulnerability/GHSA-cfgp-2977-2fmm","summary":"Connection confusion in gRPC","modified":"2026-09-10T03:49:57.873321723Z","packages":[{"ecosystem":"Maven","name":"io.grpc:grpc-protobuf","purl":"pkg:maven/io.grpc/grpc-protobuf","ranges":[">=1.53.0 <1.53.1"],"fixed":["1.53.1"]},{"ecosystem":"PyPI","name":"grpcio","purl":"pkg:pypi/grpcio","ranges":[">=1.53.0 <1.53.1"],"fixed":["1.53.1"]},{"ecosystem":"RubyGems","name":"grpc","purl":"pkg:gem/grpc","ranges":[">=1.53.0 <1.53.1"],"fixed":["1.53.1"]},{"ecosystem":"PyPI","name":"grpcio","purl":"pkg:pypi/grpcio","ranges":[">=1.54.0 <1.54.2"],"fixed":["1.54.2"]},{"ecosystem":"RubyGems","name":"grpc","purl":"pkg:gem/grpc","ranges":[">=1.54.0 <1.54.2"],"fixed":["1.54.2"]},{"ecosystem":"Maven","name":"io.grpc:grpc-protobuf","purl":"pkg:maven/io.grpc/grpc-protobuf","ranges":[">=1.54.0 <1.54.2"],"fixed":["1.54.2"]}]},{"id":"PYSEC-2026-1427","url":"https://osv.dev/vulnerability/PYSEC-2026-1427","summary":"Connection confusion in gRPC","modified":"2026-07-07T17:47:41.821414149Z","packages":[{"ecosystem":"PyPI","name":"grpcio","purl":"pkg:pypi/grpcio","ranges":[">=1.53.0 <1.53.1",">=1.54.0 <1.54.2"],"fixed":["1.53.1","1.54.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}