Vulnerability Description
Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.12, when Deno was run in BYONM mode (nodeModulesDir: "manual"), the module resolver did not validate that a package's resolved entrypoint stayed within its node_modules/<pkg>/ directory. A malicious package.json whose main field contained .. segments was able to resolve to an arbitrary path on disk, and the resolver then read that file without consulting the --allow-read allowlist. This let a require("evil-pkg") call return the contents of a file that a direct Deno.readTextFileSync(...) call would have been blocked from reading. This vulnerability is fixed in 2.7.12.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Deno | Deno | < 2.7.12 |
Related Weaknesses (CWE)
References
- https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9qExploitMitigationVendor Advisory
- https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9qExploitMitigationVendor Advisory
FAQ
What is CVE-2026-49406?
CVE-2026-49406 is a vulnerability with a CVSS score of 5.5 (MEDIUM). Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.12, when Deno was run in BYONM mode (nodeModulesDir: "manual"), the module resolver did not validate that a package's resolved e...
How severe is CVE-2026-49406?
CVE-2026-49406 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-49406?
Check the references section above for vendor advisories and patch information. Affected products include: Deno Deno.