{"cve":"CVE-2026-44726","nvd":{"published":"2026-06-23T18:17:48.623","modified":"2026-10-25T23:10:00.167","status":"Analyzed","description":"Deno is a JavaScript, TypeScript, and WebAssembly runtime. From 2.0.0 until 2.7.8, a flaw in Deno's Node.js tls compatibility layer could cause a TLS client to transmit application data in plaintext after a connection retry. When `autoSelectFamily was enabled and the first address-family attempt failed, the socket reinitialization path reused a stale TLS upgrade hook that was bound to the original, failed handle. As a result, the replacement TCP connection was never upgraded to TLS, and any data the application wrote before the secureConnect event travelled over the network unencrypted. A network attacker positioned to cause the initial connection attempt to fail (for example, by dropping IPv6 traffic on a dual-stack host) could deterministically trigger the fallback path and observe or tamper with traffic that the application believed was TLS-protected. This vulnerability is fixed in 2.7.8.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-319"],"references":["https://github.com/denoland/deno/security/advisories/GHSA-chqv-56wv-7564"],"products":["deno:deno"],"source":"nvd","synced_at":"2026-10-25T23:44:33.281319194+00:00"},"epss":{"cve":"CVE-2026-44726","score":0.00234,"percentile":0.14193,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-chqv-56wv-7564","url":"https://osv.dev/vulnerability/GHSA-chqv-56wv-7564","summary":"Deno's TLS retry copies stale upgrade hook, risking plaintext traffic","modified":"2026-07-20T14:00:26.999224608Z","packages":[{"ecosystem":"crates.io","name":"deno","purl":"pkg:cargo/deno","ranges":[">=2.0.0 <2.7.8"],"fixed":["2.7.8"]}]}],"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."]}