CVE-2026-21716: Low severity OpenJS Foundation Node.js vulnerability
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 Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-21716?
CVE-2026-21716 is considered a medium severity vulnerability due to incomplete permission checks in the promises API.
How do I fix CVE-2026-21716?
To fix CVE-2026-21716, update your Node.js version to a secure release that addresses the permissions issue.
What software versions are affected by CVE-2026-21716?
CVE-2026-21716 affects Node.js versions 20.x, 22.x, 24.x, and 25.x.
What is the nature of CVE-2026-21716 vulnerability?
The vulnerability arises from inadequate permission checks in the `FileHandle.chmod()` and `FileHandle.chown()` functions in Node.js.
Can CVE-2026-21716 lead to privilege escalation?
Yes, CVE-2026-21716 could potentially allow for privilege escalation when running code under the `--permission` flag.