CVE-2026-21716: Node.js

Low severity, CVSS 3.3. EPSS: 0.1% chance of exploitation in the next 30 days.

An incomplete fix for CVE-2024-36137 leaves `FileHandle.chmod()` and `FileHandle.chown()` in the promises API without the required permission checks, while their callback-based equivalents (`fs.fchmod()`, `fs.fchown()`) were correctly patched. As a result, code running under `--permission` with restricted `--allow-fs-write` can still use promise-based `FileHandle` methods to modify file permissions and ownership on already-open file descriptors, bypassing the intended write restrictions. This vulnerability affects **20.x, 22.x, 24.x, and 25.x** processes using the Permission Model where `--allow-fs-write` is intentionally restricted.

Affected products

• Node.js Node.js: up to and including 20.20.1; from 22.0.0, up to and including 22.22.1; from 24.0.0, up to and including 24.14.0; from 25.0.0, up to and including 25.8.1

Published 2026-03-30. Last modified 2026-08-19.