CVE-2026-49983 Deno: process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access

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 expectation is that a program running without env permission cannot...

CVE-2026-49983

Summary of CVE-2026-49983 details (Deno): Deno’s process.loadEnvFile() incorrectly bypasses env permission checks. It only verifies read permission on the dotenv file and then writes all keys from the file into process.env, even if env access is denied. This means that with --allow-read and a wri...

Deno: process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access

Summary In Deno, 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...