CVE-2026-56301: Nuxt Development Server Local File Disclosure on Linux

Technical summary

CVE-2026-56301 is an improper permission restriction vulnerability in Nuxt's vite-node IPC (Inter-Process Communication) server. On Linux, the development server binds to an abstract-namespace Unix socket without enforcing access controls (CWE-276). The unprotected module request handler in the SSR plugin pipeline allows unprivileged local users to enumerate socket endpoints and issue file read requests, bypassing file system permissions. Affected versions are Nuxt 4.0.0 through 4.4.6 and 3.18.0 through 3.21.6. The vulnerability exists only during active development (nuxt dev); production builds are unaffected because the IPC server does not run in production mode.

Business impact

Teams relying on Nuxt development environments on shared Linux systems—such as CI/CD pipelines, shared development servers, or containerized development environments—face credential exposure risk. Developers' SSH keys, API tokens stored in .env files, and database credentials could be stolen by co-resident attackers. Affected organizations should prioritize patching development and testing environments to prevent lateral movement and privilege escalation in downstream infrastructure. The risk is contained to dev-only deployments, limiting production impact but raising concerns for development velocity and shared infrastructure security.

Affected systems

Vulnerable versions: Nuxt 4.0.0 to 4.4.6 (inclusive) and Nuxt 3.18.0 to 3.21.6 (inclusive). The vulnerability is specific to Linux systems running the nuxt dev command. Windows and macOS are unaffected due to differences in Unix socket handling. Production builds using Nuxt are not at risk. Projects using Nuxt in development-only workflows or shared development environments are in scope; isolated local development on private machines has reduced risk but should still be patched.

Exploitability

Exploitation requires local system access and runs with low complexity—an attacker with unprivileged shell access can immediately connect to the abstract socket and request arbitrary files via the module handler. No authentication or user interaction is needed. This makes the vulnerability highly exploitable in multi-tenant environments, shared CI runners, and containerized setups where multiple users or build processes share a Linux kernel. However, the requirement for local access, combined with the MEDIUM CVSS score (5.5), reflects a threat model limited to insider threats and compromised sibling containers rather than remote code execution scenarios.

Remediation

Upgrade Nuxt to version 4.4.7 or later for the v4 branch, or 3.21.7 or later for the v3 branch. Verify patched versions against official Nuxt release notes and security advisories. Until patching is complete, restrict development server execution to single-user environments, use network isolation and Linux user namespacing to limit local access, and avoid running nuxt dev on shared multi-user systems. Clear .env files and SSH agent sockets after development sessions.

Patch guidance

Consult the official Nuxt project repository and security advisory for confirmed patch version numbers. For Nuxt 4.x projects, prioritize upgrading to 4.4.7 or the latest stable release. For Nuxt 3.x, upgrade to 3.21.7 or the latest patch in the v3 series. Verify the patched version has been tested in your development environment before rolling out to CI/CD pipelines. Include dependency lock file updates (package-lock.json, yarn.lock, or pnpm-lock.yaml) in your version control to ensure reproducible builds.

Detection guidance

Monitor process listings for `nuxt dev` commands on Linux systems, particularly in shared environments. Check for active abstract-namespace Unix sockets (found under /proc/net/unix) with names matching vite-node patterns. Audit file access logs around .env and SSH key directories to detect suspicious reads by unprivileged users. Correlate system logs with development activity to identify unauthorized IPC connections. Implement strict file permissions on sensitive files (mode 0600) and consider SELinux or AppArmor policies to restrict inter-process communication in development containers.

Why prioritize this

Although the CVSS score is MEDIUM (5.5), prioritize this patch in shared and multi-tenant environments because the attack surface is broad, the barrier to exploitation is low, and sensitive credentials are directly exposed. Development environments are often overlooked in patch management, making this a high-value target for internal attackers and lateral movement. Organizations with containerized dev environments or CI runners should patch immediately.

Risk score, explained

The CVSS 3.1 score of 5.5 (MEDIUM) reflects a local attack vector, low complexity, and low privilege requirements, but limited scope and confidentiality impact only. The score appropriately captures the threat in sandboxed or isolated dev environments. However, in shared infrastructure or multi-tenant scenarios, the practical risk may be elevated due to increased likelihood of co-resident attackers and the sensitivity of credentials typically stored in development environments.

Frequently asked questions