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Medium · 5.5 CVE-2026-49406 EUVD-2026-38545GHSA-968w-xfqw-vp9q

Deno: BYONM module resolution allows `package.json` main path traversal to bypass `--allow-read` restrictions

Published Jun 23, 2026 · Updated Jun 23, 2026 · Assigned by GitHub_M

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

VendorProductAffectedFixed
denoland deno < 2.7.12 —

Affected packages

EcosystemPackageAffectedFixedRecord
crates.io deno < 2.7.12 2.7.12 GHSA-968w-xfqw-vp9q

References