{"id":"CVE-2026-44726","summary":"Deno: TLS retry copies stale upgrade hook, risking plaintext traffic","details":"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.","aliases":["GHSA-chqv-56wv-7564"],"modified":"2026-07-11T03:54:43.576099423Z","published":"2026-06-23T17:24:02.702Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44726.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-319"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44726.json"},{"type":"ADVISORY","url":"https://github.com/denoland/deno/security/advisories/GHSA-chqv-56wv-7564"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44726"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/denoland/deno","events":[{"introduced":"a62c7e036ab6851c0293f407ead635a7331445b7"},{"fixed":"c394911f8edc7591de8da65c7b6690bcbc78afc1"}],"database_specific":{"cpe":"cpe:2.3:a:deno:deno:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"2.0.0"},{"fixed":"2.7.8"}],"source":["AFFECTED_FIELD","CPE_RANGE"]}}],"versions":["v2.7.7","v2.7.6","v2.7.5","v2.7.4","v2.7.3","v2.7.2","v2.7.1","v2.7.0","v2.6.10","v2.6.9","v2.6.8","v2.6.7","v2.5.6","v2.6.6","v2.6.5","v2.6.4","v2.6.3","v2.6.2","v2.6.0","v2.3.0","v2.5.5","v2.5.4","v2.5.3","v2.5.2","v2.5.1","v2.5.0","v2.4.5","v2.4.4","v2.4.3","v2.4.2","v2.4.1","v2.4.0","v2.3.7","v2.3.6","v2.3.5","v2.3.4","v2.3.3","v2.3.2","v2.3.1","v2.2.0","v2.1.0","v2.0.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-44726.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}