CVE-2026-21716

| EUVD-2026-17180 LOW
2026-03-30 hackerone
3.3
CVSS 3.0

CVSS Vector

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

Lifecycle Timeline

5
PoC Detected
Apr 01, 2026 - 14:24 vuln.today
Public exploit code
Patch Released
Mar 31, 2026 - 21:13 nvd
Patch available
Analysis Generated
Mar 30, 2026 - 19:30 vuln.today
EUVD ID Assigned
Mar 30, 2026 - 19:30 euvd
EUVD-2026-17180
CVE Published
Mar 30, 2026 - 19:07 nvd
LOW 3.3

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.

Analysis

Node.js Permission Model bypass in FileHandle.chmod() and FileHandle.chown() promise-based methods allows local authenticated users with restricted --allow-fs-write to modify file permissions and ownership on already-open file descriptors, circumventing intended write restrictions. The vulnerability affects Node.js 20.x, 22.x, 24.x, and 25.x when running under the --permission flag; the callback-based equivalents (fs.fchmod, fs.fchown) were correctly patched in CVE-2024-36137, but the promises API was incompletely fixed. …

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Priority Score

37
Low Medium High Critical
KEV: 0
EPSS: +0.0
CVSS: +16
POC: +20

Vendor Status

Ubuntu

Priority: Medium
nodejs
Release Status Version
trusty needs-triage -
xenial needs-triage -
bionic needs-triage -
focal needs-triage -
jammy needs-triage -
noble needs-triage -
questing needs-triage -
upstream released 22.22.2+dfsg+~cs22.19.15-1

Debian

nodejs
Release Status Fixed Version Urgency
bullseye vulnerable 12.22.12~dfsg-1~deb11u4 -
bullseye (security) vulnerable 12.22.12~dfsg-1~deb11u7 -
bookworm, bookworm (security) vulnerable 18.20.4+dfsg-1~deb12u1 -
trixie fixed 20.19.2+dfsg-1+deb13u2 -
trixie (security) fixed 20.19.2+dfsg-1+deb13u2 -
forky vulnerable 22.22.1+dfsg+~cs22.19.15-1 -
sid fixed 22.22.2+dfsg+~cs22.19.15-1 -
(unstable) fixed 22.22.2+dfsg+~cs22.19.15-1 -

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CVE-2026-21716 vulnerability details – vuln.today

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