Bug 2453157 (CVE-2026-21716)

Summary:	CVE-2026-21716 nodejs: Node.js: Permission bypass allows unauthorized modification of file permissions and ownership via incomplete security fix.
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	caswilli, kaycoth
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in Node.js. An incomplete security fix allows code operating under restricted file system write permissions to bypass these limitations. This vulnerability enables the modification of file permissions and ownership on already-open files, even when explicit write access is denied. Such a bypass could lead to unauthorized changes to system files.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2453592, 2453594, 2453595
Bug Blocks:

Description OSIDB Bzimport 2026-03-30 20:02:15 UTC

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.

Comment 2 errata-xmlrpc 2026-04-09 20:20:38 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:7350 https://access.redhat.com/errata/RHSA-2026:7350

Comment 3 errata-xmlrpc 2026-04-13 02:23:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:7675 https://access.redhat.com/errata/RHSA-2026:7675

Comment 4 errata-xmlrpc 2026-04-13 02:47:47 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:7670 https://access.redhat.com/errata/RHSA-2026:7670