{"id":"CVE-2023-6193","aliases":["GHSA-w3vp-jw9m-f9pm"],"title":"Unbounded queuing of path validation messages in cloudflare-quiche","summary":"Unbounded queuing of path validation messages in cloudflare-quiche","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","vendor":"quiche","product":"quiche","ecosystem":"rust","affected":["quiche >= 0.15.0, < 0.19.1"],"patched":["quiche 0.19.1"],"published":"2023-12-13","updated":"2026-07-08","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-w3vp-jw9m-f9pm","references":[{"url":"https://github.com/cloudflare/quiche/security/advisories/GHSA-w3vp-jw9m-f9pm"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-6193"},{"url":"https://github.com/cloudflare/quiche/commit/ea7ecf39ae28ab24cf1785c1674dc2e8a076f9ca"},{"url":"https://datatracker.ietf.org/doc/html/rfc9000#section-8.2"},{"url":"https://github.com/cloudflare/quiche"}],"tags":["osv","rust"],"epss":0.00763,"epssPercentile":0.53428,"ingestedAt":"2026-07-09T18:56:37.335Z","slug":"CVE-2023-6193","body":"## Overview\n\n### Impact\nquiche v. 0.15.0 through 0.19.0 was discovered to be vulnerable to unbounded queuing of path validation messages, which could lead to excessive resource consumption.\n\nQUIC path validation ([RFC 9000 Section 8.2](https://datatracker.ietf.org/doc/html/rfc9000#section-8.2)) requires that the recipient of a PATH_CHALLENGE frame responds by sending a PATH_RESPONSE. An unauthenticated remote attacker can exploit the vulnerability by sending PATH_CHALLENGE frames and manipulating the connection (e.g. by restricting the peer's congestion window size) so that PATH_RESPONSE frames can only be sent at the slower rate than they are received, leading to storage of path validation data in an unbounded queue.\n\n### Patches\nQuiche versions greater than 0.19.0 address this problem.\n\n### References\n[CVE-2023-6193](https://www.cve.org/CVERecord?id=CVE-2023-6193)\n[RFC 9000 Section 8.2](https://datatracker.ietf.org/doc/html/rfc9000#section-8.2)\n\n## Affected packages\n\n- `quiche >= 0.15.0, < 0.19.1`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `quiche 0.19.1`","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}