{"id":"CVE-2026-49859","revision":"004536d07a41427fb8aeda1e3bfc92a2","records":[{"revision":"004536d07a41427fb8aeda1e3bfc92a2","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-49859","aliases":[],"title":"Deno: `fetch()` API sandbox bypass via missing DNS resolution check","description":"Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, when fetch() was called, Deno checked the destination hostname against --deny-net rules but did not re-check the IP addresses that hostname resolved to. An attacker-controlled script could use a specially crafted domain name that passes the hostname check yet resolves to a denied IP, bypassing the network restriction entirely. This vulnerability is fixed in 2.8.1.","state":0,"publishedAt":"2026-06-23T17:14:16.888+00:00","modifiedAt":"2026-06-24T14:23:09.068+00:00","affected":[{"ecosystem":"Vendor product","name":"deno","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"denoland\",\n                    \"product\": \"deno\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 2.8.1\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","score":5.2,"severity":"MEDIUM"}],"references":["https://github.com/denoland/deno/security/advisories/GHSA-cpgj-f7g3-2pp2"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-49859","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-49859","identifiers":["CVE-2026-49859"]},"retained":false,"historicalAffected":[]}],"coverage":[]}