{"schemaVersion":3,"id":"RUSTSEC-2026-0343","aliases":["GHSA-ppcp-v39w-8jq2"],"status":"published","duplicateOf":null,"title":null,"description":"Outgoing datagram buffer accounting can panic the sender in quinn-proto\n\nThe limit on memory used to buffer outgoing datagrams, introduced in 0.11.17, subtracted an\nevicted datagram's size from the buffered byte counter twice when `Datagrams::send` was called\nwith `drop = true` (as `Connection::send_datagram` in the `quinn` crate does) while the buffer was\nfull. Under sustained eviction the counter drifts below its true value: debug builds panic with an\ninteger underflow, while release builds wrap the counter, drain the whole queue, and then panic on\na desynchronization check in a later `send` call. In `quinn`, this panic occurs while the\nconnection lock is held, poisoning it and causing a double panic (and thus an abort) when the\nconnection is dropped.\n\nThis can be triggered without a malicious peer, by an application that sends a burst of datagrams\nand then idles. It can also be triggered by a peer that keeps the connection alive with PING frames\nwhile withholding acknowledgements, so that the sender's congestion window stays closed and the\noutgoing queue never drains. Applications that use `send_datagram_wait` are not affected.\n\nOnly 0.11.17 is affected; the flaw was corrected in 0.11.18 by removing the redundant subtraction.\n\nThanks to [@alexpyattaev](https://github.com/alexpyattaev) for reporting and\n[@vcarus](https://github.com/vcarus) for fixing this issue.","dates":{"published":"2026-09-14T12:00:00.000Z","modified":"2026-10-12T18:15:01.961Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.5,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"OSV · Crates.io","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","computed":true,"selection":"version-preference"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"OSV · Crates.io","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","exploitability":10,"impact":6,"computed":true}]},"epss":{"probability":null,"percentile":null,"severity":"unknown","asOf":null,"change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[],"last30":[]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[],"affected":[{"vendor":"Crates.Io","product":"quinn-proto","name":"quinn-proto","label":"quinn-proto","ecosystem":"Crates.Io","cpePart":null,"purl":"pkg:cargo/quinn-proto","purlType":"cargo","versions":[{"text":"≥ 0.11.17, < 0.11.18","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 0.11.17, < 0.11.18","eol":null,"hubHref":null}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://crates.io/crates/quinn-proto","label":"crates.io/crates/quinn-proto","hostname":"crates.io","tags":["PACKAGE"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0343.html","label":"rustsec.org/advisories/RUSTSEC-2026-0343.html","hostname":"rustsec.org","tags":["Advisory"]},{"url":"https://github.com/quinn-rs/quinn/pull/2806","label":"github.com/quinn-rs/quinn/pull/2806","hostname":"github.com","tags":["WEB"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-09-14T12:00:00.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-10-12T18:15:01.961Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":30,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-21T17:51:14.676Z","stale":false,"partial":false}}