{"cve":"CVE-2026-49859","nvd":{"published":"2026-06-23T18:18:03.927","modified":"2026-10-25T23:10:00.167","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"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},"cwes":["CWE-693","CWE-918"],"references":["https://github.com/denoland/deno/security/advisories/GHSA-cpgj-f7g3-2pp2"],"products":["deno:deno"],"source":"nvd","synced_at":"2026-10-25T23:44:33.281319194+00:00"},"epss":{"cve":"CVE-2026-49859","score":0.00141,"percentile":0.03382,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-cpgj-f7g3-2pp2","url":"https://osv.dev/vulnerability/GHSA-cpgj-f7g3-2pp2","summary":"Deno: `fetch()` API sandbox bypass via missing DNS resolution check","modified":"2026-07-20T21:15:27.259698816Z","packages":[{"ecosystem":"crates.io","name":"deno","purl":"pkg:cargo/deno","ranges":["<2.8.1"],"fixed":["2.8.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}