{"id":"CVE-2026-49983","state":"PUBLISHED","title":"Deno: process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access","description":"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 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.","publishedAt":"2026-06-23T17:16:17.026Z","updatedAt":"2026-06-23T17:54:51.686Z","severity":{"score":5.2,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["denoland deno"],"affected":[{"vendor":"denoland","product":"deno","versions":[{"version":"< 2.8.1","status":"affected"}]}],"references":["https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv"],"weaknesses":["CWE-863"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49983.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49983","state":"PUBLISHED","datePublished":"2026-06-23T17:16:17.026Z","dateUpdated":"2026-06-23T17:54:51.686Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-02T18:30:51.282Z"},"containers":{"cna":{"title":"Deno: process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"denoland","product":"deno","versions":[{"version":"< 2.8.1","status":"affected"}]}],"references":[{"url":"https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv","name":"https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hv","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"NONE","baseScore":5.2,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-863","lang":"en","description":"CWE-863: Incorrect Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-06-23T17:16:17.026Z"},"source":{"advisory":"GHSA-4c8g-jvcx-v4hv","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-23T17:54:45.354967Z","id":"CVE-2026-49983","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-23T17:54:51.686Z"}}]}}}