CVE-2026-106073

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.

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.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

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.