{"id":"CVE-2023-32731","aliases":["GHSA-cfgp-2977-2fmm","PYSEC-2026-1427"],"url":"https://o3.security/vulnerability/CVE-2023-32731","summary":"Information leak in gRPC","details":"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 \n","published":"2023-06-09T10:54:08.472Z","modified":"2026-08-12T13:34:25.927999Z","cvss":{"score":7.4,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H"},"epss":{"score":0.00502,"percentile":0.40895,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"io.grpc:grpc-protobuf","fixedVersion":"1.53.1"},{"ecosystem":"Maven","name":"io.grpc:grpc-protobuf","fixedVersion":"1.54.2"},{"ecosystem":"PyPI","name":"grpcio","fixedVersion":"1.53.1"},{"ecosystem":"PyPI","name":"grpcio","fixedVersion":"1.54.2"},{"ecosystem":"RubyGems","name":"grpc","fixedVersion":"1.53.1"},{"ecosystem":"RubyGems","name":"grpc","fixedVersion":"1.54.2"}],"fix":{"url":"https://github.com/grpc/grpc/pull/32309","label":"grpc/grpc#32309"},"references":[{"type":"WEB","url":"https://github.com/grpc"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/32xxx/CVE-2023-32731.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-32731"},{"type":"FIX","url":"https://github.com/grpc/grpc/pull/32309"},{"type":"FIX","url":"https://github.com/grpc/grpc/pull/33005"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T13:34:25.927999Z"}}