Vulnerability · Published Oct 8, 2026 · Assigned by mongodb
CVE-2026-106436Application denial of service and data truncation via unchecked BSON append failures in MongoDB PHP Driver
Medium 4.8
In plain English
A medium-severity security flaw in PHP Driver from MongoDB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
The BSON encoder in the MongoDB PHP Driver does not check some return values after a document exceeds libbson's size limit. This can leave the encoder in an invalid state. An unauthenticated actor who can cause an affected application to encode an unusually large data structure can terminate the PHP worker or cause the resulting document to omit fields. No MongoDB server connection or database authentication is required.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | php-mongodb | no fix listed | DEBIAN-CVE-2026-106436 |
| Debian:13 | php-mongodb | 2.0.0-1+deb13u2 | DEBIAN-CVE-2026-106436 |
| Debian:14 | php-mongodb | 2.5.5-1 | DEBIAN-CVE-2026-106436 |
| Ubuntu:22.04:LTS | php-mongodb | no fix listed | UBUNTU-CVE-2026-106436 |
| Ubuntu:24.04:LTS | php-mongodb | no fix listed | UBUNTU-CVE-2026-106436 |
| Ubuntu:26.04:LTS | php-mongodb | no fix listed | UBUNTU-CVE-2026-106436 |
| Ubuntu:26.10 | php-mongodb | no fix listed | UBUNTU-CVE-2026-106436 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| MongoDB | PHP Driver | 1.3.0 – before 1.21.112.0.0 – before 2.1.112.2.0 – before 2.5.4 |
Weakness: CWE-252 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L