CVE-2026-41988: UUID Library Buffer Write Vulnerability

CVE-2026-41988 Overview

CVE-2026-41988 is an Out-of-Bounds Write vulnerability in the uuid JavaScript library affecting versions prior to 14.0.0. The vulnerability occurs when external output buffers are used with UUID versions 3, 5, or 6, leading to unexpected writes that could corrupt memory or adjacent data. Notably, UUID version 4, which is the most commonly used UUID variant, is unaffected by this issue.

Critical Impact

Applications using the uuid library with external output buffers for UUID versions 3, 5, or 6 may experience unexpected memory writes, potentially leading to data integrity issues or application instability.

Affected Products

• uuid npm package versions prior to 14.0.0
• Applications using UUID v3, v5, or v6 generation with external output buffers

Discovery Timeline

• 2026-04-23 - CVE-2026-41988 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2026-41988

Vulnerability Analysis

This vulnerability is classified under CWE-670 (Always-Incorrect Control Flow Implementation), indicating a flaw in how the uuid library manages control flow when writing to external buffers. The issue specifically manifests when applications pass an external buffer to the UUID generation functions for versions 3, 5, or 6.

The vulnerability requires local access to exploit, with high attack complexity due to the specific conditions needed for exploitation. While the integrity impact exists, no confidentiality or availability impacts have been identified, and the changed scope indicates potential impact to components beyond the vulnerable library itself.

Root Cause

The root cause lies in improper control flow handling within the uuid library when processing external output buffers. When generating UUID versions 3, 5, or 6 with a caller-provided buffer, the library performs unexpected writes that extend beyond the intended boundaries. This behavior stems from incorrect assumptions about buffer handling in the affected UUID generation code paths.

Attack Vector

The attack vector is local, requiring an attacker to have the ability to influence the input parameters to UUID generation functions within the application context. The specific conditions for exploitation include:

1. Application uses uuid library version prior to 14.0.0
2. UUID generation uses version 3, 5, or 6 (not version 4)
3. An external output buffer is provided to the generation function
4. The attacker can influence the buffer allocation or observe its state

The vulnerability could be exploited in scenarios where applications share buffers or where the unexpected writes could corrupt adjacent memory structures, potentially leading to application logic errors or denial of service conditions.

Detection Methods for CVE-2026-41988

Indicators of Compromise

• Unexpected application crashes or instability when generating UUIDs
• Memory corruption errors or buffer overrun warnings in application logs
• Anomalous behavior in applications heavily utilizing UUID v3, v5, or v6 generation

Detection Strategies

• Audit package.json and package-lock.json files for uuid library versions below 14.0.0
• Use software composition analysis (SCA) tools to identify vulnerable uuid library instances
• Monitor npm audit reports for applications using the uuid package

Monitoring Recommendations

• Implement dependency scanning in CI/CD pipelines to detect outdated uuid versions
• Configure runtime monitoring for memory-related exceptions in Node.js applications
• Review application logs for unexpected behavior patterns during UUID generation operations

How to Mitigate CVE-2026-41988

Immediate Actions Required

• Upgrade the uuid npm package to version 14.0.0 or later immediately
• Audit applications to identify usage of UUID v3, v5, or v6 with external buffers
• If immediate upgrade is not possible, avoid passing external output buffers to UUID generation functions

Patch Information

The vulnerability has been addressed in uuid version 14.0.0. The fix is available in the GitHub commit 3d2c5b0. Organizations should update their dependencies to the patched version. Additional details are available in the GitHub Security Advisory GHSA-w5hq-g745-h8pq.

Workarounds

• Avoid using external output buffers with UUID v3, v5, or v6 generation until the library is updated
• Use UUID version 4 generation which is not affected by this vulnerability
• Allocate dedicated buffers for UUID generation that are not shared with other application components

# Upgrade uuid package to patched version
npm update uuid@14.0.0

# Or explicitly install the latest version
npm install uuid@latest

# Verify installed version
npm list uuid