{"id":"CVE-2021-36153","aliases":["GHSA-2jx2-qcm4-rf9h"],"url":"https://o3.security/vulnerability/CVE-2021-36153","summary":"Incomplete Internal State Distinction in GRPCWebToHTTP2ServerCodec","details":"### Impact\n\nAffected gRPC Swift servers are vulnerable to precondition failures when parsing certain gRPC Web requests. This may lead to a denial of service.\n\n### Patches\n\nThe problem has been fixed in 1.2.0.\n\n### Workarounds\n\nNo workaround is available. Users must upgrade.","published":"2021-07-09T12:15:08.063Z","modified":"2026-07-09T12:20:05.073696Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.02082,"percentile":0.7984,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"SwiftURL","name":"github.com/grpc/grpc-swift","fixedVersion":"1.2.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35267"},{"type":"ADVISORY","url":"https://github.com/grpc/grpc-swift/releases"},{"type":"ADVISORY","url":"https://github.com/grpc/grpc-swift/security/advisories/GHSA-2jx2-qcm4-rf9h"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-36153"},{"type":"PACKAGE","url":"https://github.com/grpc/grpc-swift"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T12:20:05.073696Z"}}