{"id":"CVE-2021-32714","aliases":["RUSTSEC-2021-0079","GHSA-5h46-h7hh-c6x9"],"title":"Integer overflow in `hyper`'s parsing of the `Transfer-Encoding` header leads to data loss","summary":"Integer overflow in `hyper`'s parsing of the `Transfer-Encoding` header leads to data loss","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","vendor":"hyper","product":"hyper","ecosystem":"rust","affected":["hyper >= 0.0.0-0, < 0.14.10"],"patched":["hyper 0.14.10"],"published":"2021-07-07","updated":"2026-10-12","sourceUpdated":"2026-10-12T18:00:02.671544457Z","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/RUSTSEC-2021-0079","references":[{"url":"https://crates.io/crates/hyper"},{"url":"https://rustsec.org/advisories/RUSTSEC-2021-0079.html"},{"url":"https://github.com/hyperium/hyper/commit/efd9a9821fd2f1ae04b545094de76a435b62e70f"},{"url":"https://github.com/hyperium/hyper/security/advisories/GHSA-5h46-h7hh-c6x9"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-32714"},{"url":"https://github.com/hyperium/hyper"}],"tags":["osv","rust"],"epss":0.01155,"epssPercentile":0.66852,"ingestedAt":"2026-07-09T18:56:37.276Z","slug":"CVE-2021-32714","body":"## Overview\n\nWhen decoding chunk sizes that are too large, `hyper`'s code would encounter an integer overflow. Depending on the situation,\nthis could lead to data loss from an incorrect total size, or in rarer cases, a request smuggling attack.\n\nTo be vulnerable, you must be using `hyper` for any HTTP/1 purpose, including as a client or server, and consumers must send\nrequests or responses that specify a chunk size greater than 18 exabytes. For a possible request smuggling attack to be possible,\nany upstream proxies must accept a chunk size greater than 64 bits.\n\n## Affected packages\n\n- `hyper >= 0.0.0-0, < 0.14.10`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `hyper 0.14.10`","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[{"seq":219656,"id":"CVE-2021-32714","ts":1791891969354,"field":"cvss","old":"5.9","new":"9.1"},{"seq":219655,"id":"CVE-2021-32714","ts":1791891969354,"field":"severity","old":"medium","new":"critical"}]}