Vulnerability · Published Jun 23, 2026 · Assigned by GitHub_M
CVE-2026-49406Deno: BYONM module resolution allows `package.json` main path traversal to bypass `--allow-read` restrictions
Medium 5.5
In plain English
A medium-severity path traversal in deno from denoland. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).
Official 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.
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
References
- https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q x_refsource_CONFIRM