Bug 2431342 (CVE-2026-21636) - CVE-2026-21636 nodejs: Nodejs network segmentation bypass
Summary: CVE-2026-21636 nodejs: Nodejs network segmentation bypass
Keywords:
Status: NEW
Alias: CVE-2026-21636
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-01-20 21:02 UTC by OSIDB Bzimport
Modified: 2026-01-21 00:23 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2026-01-20 21:02:08 UTC
A flaw in Node.js's permission model allows Unix Domain Socket (UDS) connections to bypass network restrictions when `--permission` is enabled. Even without `--allow-net`, attacker-controlled inputs (such as URLs or socketPath options) can connect to arbitrary local sockets via net, tls, or undici/fetch. This breaks the intended security boundary of the permission model and enables access to privileged local services, potentially leading to privilege escalation, data exposure, or local code execution.

* The issue affects users of the Node.js permission model on version v25.

In the moment of this vulnerability, network permissions (`--allow-net`) are still in the experimental phase.


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