{"id":"CVE-2020-26281","details":"async-h1 is an asynchronous HTTP/1.1 parser for Rust (crates.io). There is a request smuggling vulnerability in async-h1 before version 2.3.0. This vulnerability affects any webserver that uses async-h1 behind a reverse proxy, including all such Tide applications. If the server does not read the body of a request which is longer than some buffer length, async-h1 will attempt to read a subsequent request from the body content starting at that offset into the body. One way to exploit this vulnerability would be for an adversary to craft a request such that the body contains a request that would not be noticed by a reverse proxy, allowing it to forge forwarded/x-forwarded headers. If an application trusted the authenticity of these headers, it could be misled by the smuggled request. Another potential concern with this vulnerability is that if a reverse proxy is sending multiple http clients' requests along the same keep-alive connection, it would be possible for the smuggled request to specify a long content and capture another user's request in its body. This content could be captured in a post request to an endpoint that allows the content to be subsequently retrieved by the adversary. This has been addressed in async-h1 2.3.0 and previous versions have been yanked.","aliases":["CVE-2020-36202","GHSA-4vr9-8cjf-vf9c","GHSA-c8rq-crxj-mj9m","RUSTSEC-2020-0093"],"modified":"2026-03-13T21:59:19.490305Z","published":"2020-12-21T22:15:13.407Z","related":["GHSA-4vr9-8cjf-vf9c"],"references":[{"type":"ADVISORY","url":"https://github.com/http-rs/async-h1/releases/tag/v2.3.0"},{"type":"ADVISORY","url":"https://github.com/http-rs/async-h1/security/advisories/GHSA-4vr9-8cjf-vf9c"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/http-rs/async-h1","events":[{"introduced":"0"},{"fixed":"b1651f3f786a0654f80dec7cbacc1f9097fecab2"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"2.3.0"}]}}],"versions":["v1.0.1","v1.0.2","v1.1.0","v1.1.1","v1.1.2","v2.0.0","v2.0.1","v2.0.2","v2.1.0","v2.1.1","v2.1.2","v2.1.3","v2.1.4","v2.2.0","v2.2.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-26281.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N"}]}