{"id":"RUSTSEC-2026-0340","summary":"Peer minimum ACK delay can panic quinn-proto when ACK_FREQUENCY transmission is enabled","details":"When sending ACK_FREQUENCY frames is enabled through\n`TransportConfig::ack_frequency_config(Some(..))`, the peer's transport parameters could cause\n`AckFrequencyState::candidate_max_ack_delay` to call `Duration::clamp` with a minimum greater\nthan its maximum, which panics.\n\nFor example, a peer advertising a `min_ack_delay` of 100,000 microseconds and a `max_ack_delay`\nof 100 milliseconds passes transport parameter validation. At a 5 ms RTT, the lower bound of the\nclamp becomes 100 ms while the upper bound is 25 ms, violating the precondition of `clamp` and\npanicking while driving the connection. Both automatically derived and explicitly configured\nmaximum ACK delays use this calculation.\n\nSending ACK_FREQUENCY frames is disabled by default, so only endpoints that opt in are affected.\n\nThe flaw was corrected in 0.11.18 by computing the delay with explicit minimum and maximum bounds\ninstead of `clamp`.\n\nThanks to [@zerox80](https://github.com/zerox80) for reporting this issue.","aliases":["GHSA-3g6h-r5qx-f6hq"],"modified":"2026-10-12T18:15:01.975478256Z","published":"2026-09-14T12:00:00Z","database_specific":{"license":"CC0-1.0"},"references":[{"type":"PACKAGE","url":"https://crates.io/crates/quinn-proto"},{"type":"ADVISORY","url":"https://rustsec.org/advisories/RUSTSEC-2026-0340.html"},{"type":"WEB","url":"https://github.com/quinn-rs/quinn/pull/2868"}],"affected":[{"package":{"name":"quinn-proto","ecosystem":"crates.io","purl":"pkg:cargo/quinn-proto"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.11.0"},{"fixed":"0.11.18"}]}],"ecosystem_specific":{"affects":{"functions":[],"arch":[],"os":[]},"affected_functions":null},"database_specific":{"source":"https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0340.json","categories":["denial-of-service"],"cvss":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","informational":null}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}