{"id":"GHSA-4q83-7cq4-p6wg","aliases":["RUSTSEC-2023-0005"],"url":"https://o3.security/vulnerability/GHSA-4q83-7cq4-p6wg","summary":"`tokio::io::ReadHalf<T>::unsplit` is Unsound","details":"`tokio::io::ReadHalf<T>::unsplit` can violate the `Pin` contract\n\nThe soundness issue is described in the [tokio/issues#5372](https://github.com/tokio-rs/tokio/issues/5372)\n\nSpecific set of conditions needed to trigger an issue (a !Unpin type in ReadHalf)\nis unusual, combined with the difficulty of making any arbitrary use-after-free\nexploitable in Rust without doing a lot of careful alignment of data types in\nthe surrounding code.\n\nThe `tokio` feature `io-util` is also required to be enabled to trigger this\nsoundness issue.\n\nThanks to zachs18 reporting the issue to Tokio team responsibly and taiki-e\nand carllerche appropriately responding and fixing the soundness bug.\n\nTokio before 0.2.0 used `futures` 0.1 that did not have `Pin`, so it is not\naffected by this issue.\n","published":"2023-02-04T00:30:37Z","modified":"2026-09-10T03:49:56.588581223Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"tokio","fixedVersion":"1.24.2"},{"ecosystem":"crates.io","name":"tokio","fixedVersion":"1.20.4"},{"ecosystem":"crates.io","name":"tokio","fixedVersion":"1.18.5"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/tokio-rs/tokio/issues/5372"},{"type":"PACKAGE","url":"https://github.com/tokio-rs/tokio"},{"type":"WEB","url":"https://rustsec.org/advisories/RUSTSEC-2023-0005.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-10T03:49:56.588581223Z"}}