Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.14, Deno's permission system enforces filesystem and execution restrictions by comparing the requested path against the path supplied to --deny-read, --deny-write, --deny-run, or --deny-ffi. On macOS, that comparison was done at the raw-byte level while the APFS filesystem treats different Unicode spellings of the same name as the same file. That means a program could reach a denied path by spelling it differently than the deny rule. This vulnerability is fixed in 2.7.14.
CVE-2026-49401
HIGHNVD 8.48.4—
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 8.4 under NVD CVSS v3. 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).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
8.4
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.4Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.4
- EG Score
- 8.4(medium)
- EPSS
- 4.0%
- KEV
- Not listed
Published
June 16, 2026
Last Modified
June 26, 2026
Advisory Details (1)
Auto-updated Jun 23, 2026Patch available. Sources: github.
github Patch Available
Deno Permission Bypass via Unicode Normalization Mismatch on macOS (APFS) · Advisory · denoland/deno · GitHub
https://github.com/denoland/deno/security/advisories/GHSA-8xpq-cjcf-3wh9Vendor Advisories for CVE-2026-49401(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 | — | 2.7.14 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Frequently asked(5)
What is CVE-2026-49401?
CVE-2026-49401 is a high vulnerability published on June 16, 2026. Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.14, Deno's permission system enforces filesystem and execution restrictions by comparing the requested path against the path supplied to --deny-read, --deny-write, --deny-run, or --deny-ffi. On macOS, that comparison was done…
When was CVE-2026-49401 disclosed?
CVE-2026-49401 was first published in the National Vulnerability Database on June 16, 2026, with the most recent update on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49401 actively exploited?
CVE-2026-49401 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 4.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-49401?
CVE-2026-49401 has a CVSS v3 base score of 8.4 (NVD).
How do I remediate CVE-2026-49401?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49401, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-49401
Is Your Infrastructure Affected by CVE-2026-49401?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.