{"id":"CVE-2020-35863","aliases":["DEBIAN-CVE-2020-35863","EUVD-2021-1736","GHSA-h3qr-rq2j-74w4","RUSTSEC-2020-0008","UBUNTU-CVE-2020-35863"],"status":"published","title":"HTTP Request Smuggling in hyper","description":"An issue was discovered in the hyper crate before 0.12.34 for Rust. HTTP request smuggling can occur. Remote code execution can occur in certain situations with an HTTP server on the loopback interface.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.02974,"percentile":0.87371,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-444"],"published":"2020-03-19T12:00:00Z","modified":"2026-10-26T12:02:00Z","fixes":[{"ecosystem":"crates.io","package":"hyper","fixed_in":["0.12.34"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:12","package":"rust-hyper","fixed_in":["0.12.35-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"rust-hyper","fixed_in":["0.12.35-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"rust-hyper","fixed_in":["0.12.35-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"hyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.11.0"},{"fixed":"0.12.34"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"rust-hyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.12.35-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"rust-hyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.12.35-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"rust-hyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.12.35-1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"hyper","ranges":[{"type":"SEMVER","events":[{"introduced":"0.11.0"},{"fixed":"0.12.34"}]}]},{"source":"osv","ecosystem":"crates.io","package":"hyper","ranges":[{"type":"SEMVER","events":[{"introduced":"0.11.0"},{"fixed":"0.12.34"}]}]}],"products":[{"vendor":"hyper","product":"hyper"}],"references":[{"url":"https://rustsec.org/advisories/RUSTSEC-2020-0008.html","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-35863","tags":["advisory"]},{"url":"https://github.com/hyperium/hyper/issues/1925","tags":["web","report"]},{"url":"https://github.com/advisories/GHSA-h3qr-rq2j-74w4"},{"url":"https://security-tracker.debian.org/tracker/CVE-2020-35863","tags":["advisory"]},{"url":"https://github.com/hyperium/hyper","tags":["package"]},{"url":"https://crates.io/crates/hyper","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2020-35863","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2020-35863","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2020-35863","description":"An issue was discovered in the hyper crate before 0.12.34 for Rust. HTTP request smuggling can occur. Remote code execution can occur in certain situations with an HTTP server on the loopback interface.","status":"published","published":"2020-12-31T08:29:46Z","modified":"2024-08-04T17:16:13.148Z","updated_at":"2026-11-02T14:35:57.975444Z"}],"euvd":[{"id":"EUVD-2021-1736","description":"An issue was discovered in the hyper crate before 0.12.34 for Rust. HTTP request smuggling can occur. Remote code execution can occur in certain situations with an HTTP server on the loopback interface.","status":"published","published":"2020-12-31T08:29:46Z","modified":"2024-08-04T17:16:13Z","updated_at":"2026-11-03T03:07:04.595509Z"}],"ghsa":[{"id":"GHSA-h3qr-rq2j-74w4","title":"HTTP Request Smuggling in hyper","description":"Vulnerable versions of hyper allow GET requests to have bodies, even if there is no Transfer-Encoding or Content-Length header. As per the HTTP 1.1 specification, such requests do not have bodies, so the body will be interpreted as a separate HTTP request.\n\nThis allows an attacker who can control the body and method of an HTTP request made by hyper to inject a request with headers that would not otherwise be allowed, as demonstrated by sending a malformed HTTP request from a Substrate runtime. This allows bypassing CORS restrictions. In combination with other vulnerabilities, such as an exploitable web server listening on loopback, it may allow remote code execution.\n\nThe flaw was corrected in hyper version 0.12.34.","status":"published","published":"2021-08-25T20:46:08Z","modified":"2023-06-13T17:40:10Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:36:53.654352Z"}],"nvd":[{"id":"CVE-2020-35863","description":"An issue was discovered in the hyper crate before 0.12.34 for Rust. HTTP request smuggling can occur. Remote code execution can occur in certain situations with an HTTP server on the loopback interface.","status":"published","published":"2020-12-31T10:15:15.097Z","modified":"2026-06-17T03:14:29.267Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:06:28.340168Z"}],"osv":[{"id":"CVE-2020-35863","description":"An issue was discovered in the hyper crate before 0.12.34 for Rust. HTTP request smuggling can occur. Remote code execution can occur in certain situations with an HTTP server on the loopback interface.","status":"published","published":"2020-12-31T10:15:15.097Z","modified":"2026-10-24T10:30:57.830563517Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:16.612899Z"},{"id":"DEBIAN-CVE-2020-35863","description":"An issue was discovered in the hyper crate before 0.12.34 for Rust. HTTP request smuggling can occur. Remote code execution can occur in certain situations with an HTTP server on the loopback interface.","status":"published","published":"2020-12-31T10:15:15.097Z","modified":"2026-10-26T12:02:00.804397581Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:45:34.019707Z"},{"id":"GHSA-h3qr-rq2j-74w4","title":"HTTP Request Smuggling in hyper","description":"Vulnerable versions of hyper allow GET requests to have bodies, even if there is no Transfer-Encoding or Content-Length header. As per the HTTP 1.1 specification, such requests do not have bodies, so the body will be interpreted as a separate HTTP request.\n\nThis allows an attacker who can control the body and method of an HTTP request made by hyper to inject a request with headers that would not otherwise be allowed, as demonstrated by sending a malformed HTTP request from a Substrate runtime. This allows bypassing CORS restrictions. In combination with other vulnerabilities, such as an exploitable web server listening on loopback, it may allow remote code execution.\n\nThe flaw was corrected in hyper version 0.12.34.","status":"published","published":"2021-08-25T20:46:08Z","modified":"2023-11-08T04:03:36.218103Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T15:46:48.546324Z"},{"id":"RUSTSEC-2020-0008","title":"Flaw in hyper allows request smuggling by sending a body in GET requests","description":"Vulnerable versions of hyper allow GET requests to have bodies, even if there is\nno Transfer-Encoding or Content-Length header.  As per the HTTP 1.1\nspecification, such requests do not have bodies, so the body will be interpreted\nas a separate HTTP request.\n\nThis allows an attacker who can control the body and method of an HTTP request\nmade by hyper to inject a request with headers that would not otherwise be\nallowed, as demonstrated by sending a malformed HTTP request from a Substrate\nruntime.  This allows bypassing CORS restrictions.  In combination with other\nvulnerabilities, such as an exploitable web server listening on loopback, it may\nallow remote code execution.\n\nThe flaw was corrected in hyper version 0.12.34.","status":"published","published":"2020-03-19T12:00:00Z","modified":"2023-11-08T04:03:36.218103Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:53:39.492624Z"},{"id":"UBUNTU-CVE-2020-35863","description":"An issue was discovered in the hyper crate before 0.12.34 for Rust. HTTP request smuggling can occur. Remote code execution can occur in certain situations with an HTTP server on the loopback interface.","status":"withdrawn","published":"2020-12-31T10:15:00Z","modified":"2025-07-16T07:41:35.361448Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:54:25.179924Z"}]}}