{"id":"CVE-2023-26964","aliases":["GHSA-f8vr-r385-rh5r","RUSTSEC-2023-0034"],"url":"https://o3.security/vulnerability/CVE-2023-26964","summary":"h2 vulnerable to denial of service","details":"Hyper is an HTTP library for Rust and h2 is an HTTP 2.0 client & server implementation for Rust. An issue was discovered in h2 v0.2.4 when processing header frames. It incorrectly processes the HTTP2 `RST_STREAM` frames by not always releasing the memory immediately upon receiving the reset frame, leading to stream stacking. As a result, the memory and CPU usage are high which can lead to a Denial of Service (DoS).\n\nThis issue affects users only when dealing with http2 connections.","published":"2023-04-11T00:00:00Z","modified":"2026-08-12T03:51:17.486906090Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.01121,"percentile":0.64415,"asOf":"2026-09-15"},"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"crates.io","name":"h2","fixedVersion":"0.3.17"}],"fix":{"url":"https://github.com/hyperium/h2/pull/668","label":"hyperium/h2#668"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/26xxx/CVE-2023-26964.json"},{"type":"ADVISORY","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZHBAE7LQARMPUEEV4TWET4D7G6WCWBUD/"},{"type":"ADVISORY","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZYRZ5Y2ALATKKPIITAFAJIS4TR4LUAHO/"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-26964"},{"type":"REPORT","url":"https://github.com/hyperium/hyper/issues/2877"},{"type":"WEB","url":"https://github.com/hyperium/h2/issues/621"},{"type":"WEB","url":"https://github.com/hyperium/h2/pull/668"},{"type":"PACKAGE","url":"https://github.com/hyperium/hyper"},{"type":"WEB","url":"https://rustsec.org/advisories/RUSTSEC-2023-0034.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:17.486906090Z"}}