Quick answers
- Is CVE-2026-49983 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-49983 being exploited in the wild.
- How severe is CVE-2026-49983?
- Medium severity, with a CVSS score of 5.2, published 23 June 2026.
- Which products and versions are affected?
- deno (crates.io) <= 2.8.0, SEMVER:introduced=0,fixed=2.8.1.
- Is there a fix for CVE-2026-49983?
- Yes. deno (crates.io): upgrade to 2.8.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-49983 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-49983?
- Check whether you run deno (crates.io) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- deno (crates.io): upgrade to 2.8.1 or later
cargo update -p deno
Technical details
An authorization bypass exists in Deno's Node-compatible 'process.loadEnvFile()' API. While Deno normally gates environment access via the '--allow-env' or '--deny-env' flags, this specific function only validates file read permissions ('--allow-read') before writing keys from a .env file into 'process.env'. A local attacker or malicious dependency that can control a .env file can effectively bypass environment restrictions to mutate the process environment. This issue affects Deno versions 2.3.0 through 2.8.0 and is resolved in version 2.8.1.
Affected products
- denoland Deno >= 2.3.0, < 2.8.1
Identifiers
- CVE-2026-49983
- GHSA-4c8g-jvcx-v4hv
Timeline
- 2026-05-27: advisory: GitHub advisory published by denoland
- 2026-06-23: disclosed: CVE published to NVD
- 2026-06-23: patched: Fix released in version 2.8.1