Node.js Permission Model Bypass via fs.realpathSync.native()
CVE-2026-21715 Published on March 30, 2026
A flaw in Node.js Permission Model filesystem enforcement leaves `fs.realpathSync.native()` without the required read permission checks, while all comparable filesystem functions correctly enforce them. As a result, code running under `--permission` with restricted `--allow-fs-read` can still use `fs.realpathSync.native()` to check file existence, resolve symlink targets, and enumerate filesystem paths outside of permitted directories. This vulnerability affects **20.x, 22.x, 24.x, and 25.x** processes using the Permission Model where `--allow-fs-read` is intentionally restricted.
Weakness Type
Incorrect Permission Assignment for Critical Resource
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors. When a resource is given a permissions setting that provides access to a wider range of actors than required, it could lead to the exposure of sensitive information, or the modification of that resource by unintended parties. This is especially dangerous when the resource is related to program configuration, execution or sensitive user data.
Affected Versions
nodejs node:- Version 20.20.1, <= 20.20.1 is affected.
- Version 22.22.1, <= 22.22.1 is affected.
- Version 24.14.0, <= 24.14.0 is affected.
- Version 25.8.1, <= 25.8.1 is affected.
- Version 4.0 and below 4.* is affected.
- Version 5.0 and below 5.* is affected.
- Version 6.0 and below 6.* is affected.
- Version 7.0 and below 7.* is affected.
- Version 8.0 and below 8.* is affected.
- Version 9.0 and below 9.* is affected.
- Version 10.0 and below 10.* is affected.
- Version 11.0 and below 11.* is affected.
- Version 12.0 and below 12.* is affected.
- Version 13.0 and below 13.* is affected.
- Version 14.0 and below 14.* is affected.
- Version 15.0 and below 15.* is affected.
- Version 16.0 and below 16.* is affected.
- Version 17.0 and below 17.* is affected.
- Version 18.0 and below 18.* is affected.
- Version 19.0 and below 19.* is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.