CVE-2026-49406
Deno: BYONM module resolution allows `package.json` main path traversal to bypass `--allow-read` restrictions
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.
INFO
Published Date :
June 23, 2026, 6:18 p.m.
Last Modified :
June 26, 2026, 5:29 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Deno to version 2.7.12 or later.
- Ensure packages do not use '..' in main field.
- Validate package.json entrypoints carefully.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-49406.
| URL | Resource |
|---|---|
| https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q | Exploit Mitigation Vendor Advisory |
| https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-49406 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-49406
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-49406 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-49406 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 26, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:deno:deno:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.12 Added Reference Type GitHub, Inc.: https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q Types: Exploit, Mitigation, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q Types: Exploit, Mitigation, Vendor Advisory -
New CVE Received by [email protected]
Jun. 23, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'denoland', 'product': 'deno', 'versions': [{'status': 'affected', 'version': '< 2.7.12'}]}] Added 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. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-22 Added Reference https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 23, 2026
Action Type Old Value New Value Added Reference https://github.com/denoland/deno/security/advisories/GHSA-968w-xfqw-vp9q Added SSVC {'id': 'CVE-2026-49406', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-23T17:49:51.311695Z'}