{"id":"CVE-2021-38512","aliases":["GHSA-8928-2fgm-6x9x","RUSTSEC-2021-0081"],"url":"https://o3.security/vulnerability/CVE-2021-38512","summary":"HTTP Request Smuggling in actix-http","details":"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.","published":"2021-08-10T23:15:07.277Z","modified":"2026-07-08T05:57:17.690920039Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"crates.io","name":"actix-http","fixedVersion":"2.2.1"}],"fix":{"url":"https://github.com/actix/actix-web/pull/2363","label":"actix/actix-web#2363"},"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/67URRW4K47SR6LNQB4YALPLGGQMQK7HO/"},{"type":"ADVISORY","url":"https://rustsec.org/advisories/RUSTSEC-2021-0081.html"},{"type":"EVIDENCE","url":"https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/actix-http/RUSTSEC-2021-0081.md"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-38512"},{"type":"WEB","url":"https://github.com/actix/actix-web/pull/2363"},{"type":"WEB","url":"https://github.com/actix/actix-web/commit/e965d8298f421e9c89fe98b1300b8361e948c324"},{"type":"PACKAGE","url":"https://github.com/actix/actix-web"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/67URRW4K47SR6LNQB4YALPLGGQMQK7HO"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T05:57:17.690920039Z"}}