---
id: CVE-2025-55131
title: >-
  A flaw in Node.js's buffer allocation logic can expose uninitialized memory
  when allocations are interrupted, when using the `vm` module with the timeout
  option
summary: >-
  A flaw in Node.js's buffer allocation logic can expose uninitialized memory
  when allocations are interrupted, when using the `vm` module with the timeout
  option. Under specific timing conditions, buffers allocated with
  `Buffer.alloc` and…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L'
cwe:
  - CWE-120
  - CWE-497
published: '2026-01-20'
updated: '2026-06-30'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-55131'
references:
  - url: 'https://nodejs.org/en/blog/vulnerability/december-2025-security-releases'
    label: support@hackerone.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:1842'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:1843'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2420'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2421'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2422'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2767'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2768'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2781'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2782'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2783'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2864'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:2899'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6402'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:6431'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:7386'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:7387'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2025-55131'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2431350'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-55131.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
tags:
  - nvd
epss: 0.03507
epssPercentile: 0.88668
ingestedAt: '2026-06-30T13:26:50.523Z'
---

## Overview

A flaw in Node.js's buffer allocation logic can expose uninitialized memory when allocations are interrupted, when using the `vm` module with the timeout option. Under specific timing conditions, buffers allocated with `Buffer.alloc` and other `TypedArray` instances like `Uint8Array` may contain leftover data from previous operations, allowing in-process secrets like tokens or passwords to leak or causing data corruption. While exploitation typically requires precise timing or in-process code execution, it can become remotely exploitable when untrusted input influences workload and timeouts, leading to potential confidentiality and integrity impact.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.