CVE-2025-14178
Heap Buffer Overflow in PHP array_merge() Causes Memory Corruption
Publication date: 2025-12-27
Last updated on: 2025-12-27
Assigner: PHP Group
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| php | php | 8.5 |
| php | php | 8.2 |
| php | php | 8.3 |
| php | php | 8.1 |
| php | php | 8.4 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
| CWE-190 | The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided resources do not specify how this vulnerability affects compliance with common standards and regulations such as GDPR or HIPAA.
Can you explain this vulnerability to me?
This vulnerability is a heap buffer overflow in PHP's array_merge() function that occurs when merging packed arrays whose total element count exceeds 32-bit limits or HT_MAX_SIZE. It is caused by an integer overflow during the precomputation of element counts using zend_hash_num_elements(), which can lead to memory corruption or crashes.
How can this vulnerability impact me? :
The vulnerability can lead to memory corruption or crashes on the target server, potentially affecting the server's integrity and availability.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by checking if your PHP environment is running a vulnerable version prior to 8.1.34, 8.2.30, 8.3.29, 8.4.16, or 8.5.1. Additionally, detection can involve monitoring for usage of the array_merge() function with very large arrays that could exceed 32-bit limits or HT_MAX_SIZE. A practical test command in PHP to check for vulnerability is to run code that attempts to merge large arrays, such as: ```php $arr = range(0, 2**29); array_merge($arr, $arr, $arr, $arr, $arr, $arr, $arr, $arr); ``` If this causes a crash or memory corruption, the system is vulnerable. For version checking, you can run `php -v` to see the installed PHP version. There are no specific network commands mentioned for detection. [1]
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include upgrading PHP to a patched version: 8.1.34 or later, 8.2.30 or later, 8.3.29 or later, 8.4.16 or later, or 8.5.1 or later. As a workaround, avoid merging a large number of long arrays using array_merge(), especially when the total element count could exceed 32-bit integer limits or HT_MAX_SIZE. Monitoring and restricting inputs that could lead to large arrays, such as large JSON arrays decoded and passed to array_merge(), can also help mitigate exploitation. [1]