---
id: CVE-2025-14178
title: >-
  In PHP versions:8.1.* before 8.1.34, 8.2.* before 8.2.30, 8.3.* before 8.3.29,
  8.4.* before 8.4.16, 8.5.* before 8.5.1, a heap buffer overflow occurs in
  array_merge() when the total element count of packed arrays exceeds 32-bit
  limits or…
summary: >-
  In PHP versions:8.1.* before 8.1.34, 8.2.* before 8.2.30, 8.3.* before 8.3.29,
  8.4.* before 8.4.16, 8.5.* before 8.5.1, a heap buffer overflow occurs in
  array_merge() when the total element count of packed arrays exceeds 32-bit
  limits or…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H'
cwe:
  - CWE-190
  - CWE-787
  - CWE-190
vendor: php
product: php
affected:
  - 'php >= 8.1.0, < 8.1.34'
  - 'php >= 8.2.0, < 8.2.30'
  - 'php >= 8.3.0, < 8.3.29'
  - 'php >= 8.4.0, < 8.4.16'
  - 'php >= 8.5.0, < 8.5.1'
patched:
  - php 8.5.1
published: '2025-12-27'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T09:10:00.323'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-14178'
references:
  - url: 'https://github.com/php/php-src/security/advisories/GHSA-h96m-rvf9-jgm2'
    label: security@php.net
  - url: 'https://lists.debian.org/debian-lts-announce/2026/01/msg00019.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00459
epssPercentile: 0.37909
ingestedAt: '2026-10-13T09:20:23.161Z'
---

## Overview

In PHP versions:8.1.* before 8.1.34, 8.2.* before 8.2.30, 8.3.* before 8.3.29, 8.4.* before 8.4.16, 8.5.* before 8.5.1, a heap buffer overflow occurs in array_merge() when the total element count of packed arrays exceeds 32-bit limits or HT_MAX_SIZE, due to an integer overflow in the precomputation of element counts using zend_hash_num_elements(). This may lead to memory corruption or crashes and affect the integrity and availability of the target server.

## Affected

- `php >= 8.1.0, < 8.1.34`
- `php >= 8.2.0, < 8.2.30`
- `php >= 8.3.0, < 8.3.29`
- `php >= 8.4.0, < 8.4.16`
- `php >= 8.5.0, < 8.5.1`

## Remediation

Upgrade past the affected range:

- `php 8.5.1`