CVE-2026-106436: php driver — Fix

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.

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CVSS v3.1 Score

4.8

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

EPSS — Exploit Prediction

0.0026

Probability of exploitation

0.16%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-252 CWE-252

Affected Products

Vendor	Product	Versions
mongodb	php_driver	1.3.0 — 1.21.1
mongodb	php_driver	2.0.0 — 2.1.11
mongodb	php_driver	2.2.0 — 2.5.4

References

Advisories & Patches

https://jira.mongodb.org/browse/PHPC-2739

Frequently Asked Questions

What is CVE-2026-106436? +

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. It has a CVSS v3.1 base score of 4.8 (MEDIUM).

How severe is CVE-2026-106436? +

CVE-2026-106436 has a CVSS v3.1 score of 4.8 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-106436? +

CVE-2026-106436 affects products from mongodb, specifically: php_driver. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-106436? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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