{"id":"CVE-2021-38512","aliases":["EUVD-2021-1635","GHSA-8928-2fgm-6x9x","RUSTSEC-2021-0081"],"status":"published","title":"HTTP Request Smuggling in actix-http","description":"An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.0181,"percentile":0.78931,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-444"],"published":"2021-06-16T12:00:00Z","modified":"2026-10-24T10:30:52Z","fixes":[{"ecosystem":"crates.io","package":"actix-http","fixed_in":["2.2.1","3.0.0-beta.9"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"actix-http","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.2.1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"actix-http","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.2.1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"actix-http","ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"2.2.1"},{"introduced":"3.0.0-0"},{"fixed":"3.0.0-beta.9"}]}]}],"products":[{"vendor":"actix","product":"actix-http"},{"vendor":"fedoraproject","product":"fedora"}],"references":[{"url":"https://rustsec.org/advisories/RUSTSEC-2021-0081.html","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/actix-http/RUSTSEC-2021-0081.md","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence","web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/67URRW4K47SR6LNQB4YALPLGGQMQK7HO/","tags":["vendor-advisory","x_refsource_FEDORA","x_transferred","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-38512","tags":["advisory"]},{"url":"https://github.com/actix/actix-web/pull/2363","tags":["web"]},{"url":"https://github.com/actix/actix-web/commit/e965d8298f421e9c89fe98b1300b8361e948c324","tags":["web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/67URRW4K47SR6LNQB4YALPLGGQMQK7HO/"},{"url":"https://github.com/advisories/GHSA-8928-2fgm-6x9x"},{"url":"https://github.com/actix/actix-web","tags":["package"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/67URRW4K47SR6LNQB4YALPLGGQMQK7HO","tags":["web"]},{"url":"https://crates.io/crates/actix-http","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-38512","description":"An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.","status":"published","published":"2021-08-10T22:12:31Z","modified":"2024-08-04T01:44:22.927Z","updated_at":"2026-11-02T14:33:07.349244Z"}],"euvd":[{"id":"EUVD-2021-1635","description":"An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.","status":"published","published":"2021-08-10T22:12:31Z","modified":"2024-08-04T01:44:22Z","updated_at":"2026-11-03T03:24:25.244479Z"}],"ghsa":[{"id":"GHSA-8928-2fgm-6x9x","title":"HTTP Request Smuggling in actix-http","description":"Affected versions of this crate did not properly detect invalid requests that could allow HTTP/1 request smuggling (HRS) attacks when running alongside a vulnerable front-end proxy server. This can result in leaked internal and/or user data, including credentials, when the front-end proxy is also vulnerable.\n\nPopular front-end proxies and load balancers already mitigate HRS attacks so it is recommended that they are also kept up to date; check your specific set up. You should upgrade even if the front-end proxy receives exclusively HTTP/2 traffic and connects to the back-end using HTTP/1; several downgrade attacks are known that can also expose HRS vulnerabilities.","status":"published","published":"2021-08-25T20:58:21Z","modified":"2023-02-03T05:05:56Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:36:42.703723Z"}],"nvd":[{"id":"CVE-2021-38512","description":"An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.","status":"published","published":"2021-08-10T23:15:07.277Z","modified":"2026-06-17T04:02:15.62Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:P/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:06:56.943671Z"}],"osv":[{"id":"CVE-2021-38512","description":"An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.","status":"published","published":"2021-08-10T23:15:07.277Z","modified":"2026-10-24T10:30:52.979843906Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T15:44:20.843843Z"},{"id":"GHSA-8928-2fgm-6x9x","title":"HTTP Request Smuggling in actix-http","description":"Affected versions of this crate did not properly detect invalid requests that could allow HTTP/1 request smuggling (HRS) attacks when running alongside a vulnerable front-end proxy server. This can result in leaked internal and/or user data, including credentials, when the front-end proxy is also vulnerable.\n\nPopular front-end proxies and load balancers already mitigate HRS attacks so it is recommended that they are also kept up to date; check your specific set up. You should upgrade even if the front-end proxy receives exclusively HTTP/2 traffic and connects to the back-end using HTTP/1; several downgrade attacks are known that can also expose HRS vulnerabilities.","status":"published","published":"2021-08-25T20:58:21Z","modified":"2023-11-08T04:06:27.940101Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T15:46:42.077781Z"},{"id":"RUSTSEC-2021-0081","title":"Potential request smuggling capabilities due to lack of input validation","description":"Affected versions of this crate did not properly detect invalid requests that could allow HTTP/1 request smuggling (HRS) attacks when running alongside a vulnerable front-end proxy server. This can result in leaked internal and/or user data, including credentials, when the front-end proxy is also vulnerable.\n\nPopular front-end proxies and load balancers already mitigate HRS attacks so it is recommended that they are also kept up to date; check your specific set up. You should upgrade even if the front-end proxy receives exclusively HTTP/2 traffic and connects to the back-end using HTTP/1; several downgrade attacks are known that can also expose HRS vulnerabilities.","status":"published","published":"2021-06-16T12:00:00Z","modified":"2023-11-08T04:06:27.940101Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T15:53:39.492624Z"}]}}