CVE-2025-14178: PHP

High severity, CVSS 8.2. EPSS: 0.5% chance of exploitation in the next 30 days.

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 products

• PHP PHP: from 8.1.0, before 8.1.34 (fixed in 8.1.34); from 8.2.0, before 8.2.30 (fixed in 8.2.30); from 8.3.0, before 8.3.29 (fixed in 8.3.29); from 8.4.0, before 8.4.16 (fixed in 8.4.16); from 8.5.0, before 8.5.1 (fixed in 8.5.1)

Published 2025-12-27. Last modified 2026-06-17.