Description
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.
CVSS Metrics
- Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
- Attack Vector
- network
- Complexity
- high
- Privileges
- none
- User Action
- none
- Scope
- unchanged
- Confidentiality
- none
- Integrity
- low
- Availability
- high
- Weaknesses
- CWE-190CWE-787CWE-190
Metadata
- Primary Vendor
- PHP
- Published
- 12/27/2025
- Last Modified
- 1/24/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
php : phpphp : phpphp : phpphp : phpphp : php
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