{"id":"CVE-2026-55517","revision":"ad14a5ec0c024a68825a692d496034c0","records":[{"revision":"ad14a5ec0c024a68825a692d496034c0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-55517","aliases":[],"title":"Deno: Denial of service via non-ASCII bytes in WebSocket response headers","description":"Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, a Deno program that opens a client WebSocket connection could be crashed by the remote server. While handling the WebSocket handshake response, Deno parsed the Sec-WebSocket-Protocol and Sec-WebSocket-Extensions response headers in a way that assumed their bytes were always printable ASCII. A response header containing non-visible-ASCII bytes (0x80-0xFF) caused a panic that aborted the entire Deno process. This vulnerability is fixed in 2.7.5.","state":0,"publishedAt":"2026-06-23T17:24:59.498+00:00","modifiedAt":"2026-06-23T17:52:56.96+00:00","affected":[{"ecosystem":"Vendor product","name":"deno","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"denoland\",\n                    \"product\": \"deno\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 2.7.5\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","score":4.3,"severity":"MEDIUM"}],"references":["https://github.com/denoland/deno/security/advisories/GHSA-x2qc-cmh9-f4hf"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-55517","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-55517","identifiers":["CVE-2026-55517"]},"retained":false,"historicalAffected":[]}],"coverage":[]}