{"id":"CVE-2026-49983","title":"Deno is a JavaScript, TypeScript, and WebAssembly runtime","summary":"Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, environment access is gated by the env permission. You can deny it with --deny-env, or restrict it to a specific allowlist with --allow-env=FOO,BAR. The expectati…","severity":"medium","cvss":5.2,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","cwe":["CWE-863"],"published":"2026-06-23","updated":"2026-06-29","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-49983","references":[{"url":"https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.0014,"epssPercentile":0.03705,"ingestedAt":"2026-06-29T13:42:11.981Z","slug":"CVE-2026-49983","body":"## Overview\n\nDeno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.8.1, environment access is gated by the env permission. You can deny it with --deny-env, or restrict it to a specific allowlist with --allow-env=FOO,BAR. The expectation is that a program running without env permission cannot change process.env. process.loadEnvFile() (the Node-compatible API for loading variables from a .env file) does not honor this. It only checks that the program has read permission for the dotenv file, then writes every key in that file into the process environment — even when env access is denied. In effect, --allow-read plus a writable or attacker-controlled .env file is enough to defeat --deny-env. This vulnerability is fixed in 2.8.1.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":28.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}