CVE-2026-21716: 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.
Overview
- Severity
- Low (CVSS 3.3)
- CVSS Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- Exploit Status
- Not Exploited
- Patch Tuesday
- 2026-Mar
- Released
- 2026-04-01
- Last Updated
- 2026-04-09
- EPSS Score
- 0.16% (percentile: 5.4%)
Affected Products (2)
Open Source Software
- azl3 nodejs24 24.13.0-3 on Azure Linux 3.0
Other
Revision History
- 2026-04-01: Information published.
- 2026-04-08: Information published.
- 2026-04-09: Information published.