CVE-2026-21715

Description

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.

How to fix CVE-2026-21715

To remediate CVE-2026-21715, upgrade the affected package to a fixed version below.

• —upgrade to 22.22.2-r0 or later
• —upgrade to 20.20.2 or later
• —upgrade to 20.20.2 or later
• —upgrade to 20.19.2+dfsg-1+deb13u2 or later

Is CVE-2026-21715 being exploited?

Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.

Affected packages (4)

• from 0, < 22.22.2-r0
• from 0, < 20.20.2, >= 21.0.0, < 22.22.2, >= 23.0.0, < 24.14.1, >= 25.0.0, < 25.8.2
• from 0, < 20.20.2, >= 21.0.0, < 22.22.2, >= 23.0.0, < 24.14.1, >= 25.0.0, < 25.8.2
• from 0, < 20.19.2+dfsg-1+deb13u2

CVSS scores

References (4)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2026-21715
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2026-21715
• WEBnodejs.org/en/blog/vulnerability/march-2026-security-releases
• WEBnvd.nist.gov/vuln/detail/CVE-2026-21715