What is CVE-2026-49983?

CVE-2026-49983 is a medium-severity vulnerability in Deno, classified under Incorrect Authorization. CVSS score: 5.2/10. Published 2026-06-23.

How severe is CVE-2026-49983?

Medium severity. CVSS v3 base score is 5.2 out of 10.

Auth bypass in Deno

CVE-2026-49983

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…

Vulnerability class: Broken Access Control

EPSS: 0.001 (0.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.2 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

Affected products

Deno
Denoland Deno — versions < 2.8.1

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-49983?: CVE-2026-49983 is a medium-severity vulnerability in Deno, classified under Incorrect Authorization. CVSS score: 5.2/10. Published 2026-06-23.
How severe is CVE-2026-49983?: Medium severity. CVSS v3 base score is 5.2 out of 10.