CVE-2026-21636
A flaw in Node.js's permission model allows Unix Domain Socket (UDS) connections to bypass network restrictions when `--permission` is enabled.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.83%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 10.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.83% probability · 55th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-284
- Affected
- nodejs/node.js
- Source
- support@hackerone.com
References
- https://nodejs.org/en/blog/vulnerability/december-2025-security-releasesRelease Notes, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.