CVE-2026-21716 — LOW (3.3) — White Hats Nepal

Vulnerability Description

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.

CVSS Score

3.3

LOW

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-862

References

https://nodejs.org/en/blog/vulnerability/march-2026-security-releases

FAQ

What is CVE-2026-21716?

CVE-2026-21716 is a vulnerability with a CVSS score of 3.3 (LOW). 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...

How severe is CVE-2026-21716?

CVE-2026-21716 has been rated LOW with a CVSS base score of 3.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-21716?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.