CVE-2026-106073
Description
A flaw was found in the Node.js Permission Model. fs.realpathSync() does not perform the filesystem read permission checks required of comparable fs APIs. This is an incomplete fix of CVE-2026-21715, which only covered fs.realpathSync.native(). Code running under --permission with restricted --allow-fs-read can still use fs.realpathSync() to probe file existence, resolve symlink targets, and enumerate paths outside permitted directories, leading to information disclosure.
Statement
This is a Low severity flaw. Red Hat rates it Low, consistent with CVE-2026-21715, because impact is limited to confidentiality of path existence and symlink resolution (Confidentiality Low), and the Permission Model is an opt-in experimental control. Integrity and availability are not affected. Deployments that do not use --permission are not exposed. Platform MAC (SELinux) may still constrain process file access outside the Permission Model but is not assumed to replace Node.js checks in the base score.
Mitigation
If the Permission Model is unused, do not enable --permission.
When --permission is required, avoid relying on fs.realpathSync() for security boundaries; use APIs that enforce permission checks and keep --allow-fs-read minimal.
Apply OS-level confinement (SELinux, containers) as defense in depth.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.3 | N/A | 3.3 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Red Hat CVSS v3 Score Explanation
Aligned with CNA and RH scoring for CVE-2026-21715. Incomplete fix: realpathSync.native was covered; fs.realpathSync() remained unchecked. C:L path enumeration under opt-in --permission.
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