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Medium 5.2Published Jun 23, 2026

CVE-2026-49983Deno is a JavaScript, TypeScript, and WebAssembly runtime.

Updated under an hour ago ()

Does this affect you?

It affects deno. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
5.2 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Weakness (CWE)
CWE-863
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Analyzed
Record last updated
Jun 29, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
deno deno
deno:deno
from 2.3.0 before 2.8.1
NVD

References

  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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