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.
CVE-2026-49983
This medium-severity CVE scores 5.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 96% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.2
- EG Score
- 5.2(medium)
- EG Risk
- 28(Track)EG Risk 28/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity52% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 4%
- KEV
- Not listed
Published
June 16, 2026
Last Modified
June 29, 2026
Advisory Details (1)
Auto-updated Jun 23, 2026process.loadEnvFile() bypasses env permission checks and mutates process.env with only read access · Advisory · denoland/deno · GitHub
https://github.com/denoland/deno/security/advisories/GHSA-4c8g-jvcx-v4hvVendor Advisories for CVE-2026-49983(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
crates.io(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| deno | — | 2.8.1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 42× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-24 23:24 UTCEG score recompute
- 2026-08-23 09:25 UTCEG score recompute
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-21 17:38 UTCEG score recompute
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 16:18 UTCEG score recompute
- 2026-08-19 17:04 UTCEPSS rescore
- 2026-08-19 13:07 UTCEG score recompute
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-17 00:58 UTCEG score recompute
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-16 00:26 UTCEG score recompute
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-13 23:25 UTCEG score recompute
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-12 22:53 UTCEG score recompute
- 2026-08-12 13:51 UTCEPSS rescore
- 2026-08-11 22:22 UTCEG score recompute
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-09 21:21 UTCEG score recompute
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-08 20:51 UTCEG score recompute
- 2026-08-08 16:37 UTCEPSS rescore
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- 2026-08-07 20:20 UTCEG score recompute
- 2026-08-06 19:50 UTCEG score recompute
- 2026-08-06 13:47 UTCEPSS rescore
- 2026-08-05 19:19 UTCEG score recompute
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 15:36 UTCEG score recompute
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 10:39 UTCEPSS rescore
- 2026-08-01 08:19 UTCEG score recompute
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-31 04:44 UTCEG score recompute
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 04:14 UTCEG score recompute
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-29 03:03 UTCEG score recompute
- 2026-07-28 15:37 UTCEPSS rescore
- 2026-07-28 01:38 UTCEG score recompute
- 2026-07-26 19:50 UTCEG score recompute
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:18 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-13 22:30 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-08 15:16 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:07 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-27 03:08 UTCEPSS rescore
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-24 14:05 UTCEPSS rescore
- 2026-06-16 19:06 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-863
Frequently asked(5)
What is CVE-2026-49983?
When was CVE-2026-49983 disclosed?
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What is the CVSS score of CVE-2026-49983?
How do I remediate CVE-2026-49983?
Dependency Blast Radius
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