CVE-2026-106432: MongoDB PHP Driver

Low severity, CVSS 3.6. EPSS: 0.1% chance of exploitation in the next 30 days.

The BSON encoder in the MongoDB PHP Driver converts a string length to a 32-bit value without validation. When an affected application encodes a string near 4 GiB, the allocation size can wrap while the copy operation uses the original length. The resulting heap buffer overflow can corrupt process memory or terminate the PHP process. Reaching this issue requires a non-default runtime configuration that permits multi-gigabyte values. No MongoDB server interaction is required.

Affected products

• MongoDB PHP Driver: from 1.16.0, before 1.21.11 (fixed in 1.21.11); from 2.0.0, before 2.1.11 (fixed in 2.1.11); from 2.2.0, before 2.5.4 (fixed in 2.5.4)

Published 2026-10-08. Last modified 2026-10-08.