Auth bypass in Node.js Node
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.001 (3.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000
Affected products
- Node.js Node — versions 20.20.1, 22.22.1, 24.14.0
- Node.js
Weakness classification (CWE)
References
- nodejs.org/en/blog/vulnerability/march-2026-security-releases (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-21716?
- CVE-2026-21716 is a low-severity vulnerability in Node.js Node, classified under Missing Authorization. CVSS score: 3.3/10. Published 2026-03-30.
- How severe is CVE-2026-21716?
- Low severity. CVSS v3 base score is 3.3 out of 10.