CVE-2026-21716

Filesystem restriction bypass via unchecked FileHandle methods

Published Mar 30, 2026 · Updated Mar 30, 2026

Missing authorization in Node.js 20.x, 22.x, 24.x, and 25.x allows local users to alter file permissions and ownership. FileHandle.chmod() and FileHandle.chown() in the promises API invoke fchmod and fchown without first enforcing Permission Model write authorization on the open descriptor. Reachability requires code execution under --permission with restricted --allow-fs-write and an already-open descriptor, permitting only metadata changes allowed by the host account.

CVSS severity3.3
Low
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Missing authorization in Node.js 20.x, 22.x, 24.x, and 25.x allows local users to alter file permissions and ownership. FileHandle.chmod() and FileHandle.chown() in the promises API invoke fchmod and fchown without first enforcing Permission Model write authorization on the open descriptor. Reachability requires code execution under --permission with restricted --allow-fs-write and an already-open descriptor, permitting only metadata changes allowed by the host account.

The record

CVE
CVE-2026-21716
Published
Mar 30, 2026
Updated
Mar 30, 2026
Vendor
Node.js
Product
Node.js
Classifications
CWE-862, T1222.002
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 30, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=20.20.1 <=20.20.1
  2. Affected versionversion=22.22.1 <=22.22.1
  3. Affected versionversion=24.14.0 <=24.14.0
  4. Affected versionversion=25.8.1 <=25.8.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Node.js · Node.jsversion=20.20.1 <=20.20.1; version=22.22.1 <=22.22.1; version=24.14.0 <=24.14.0; version=25.8.1 <=25.8.1

Published CVSS scores

3.3HackerOneCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1222.002File and Directory Permissions Modification: Linux and Mac Permissions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo