# CVE-2026-106436: Application denial of service and data truncation via unchecked BSON append failures in MongoDB PHP Driver

> CVE-2026-106436: Application denial of service and data truncation via unchecked BSON append failures in MongoDB PHP Driver. CVSS 4.8 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-106436
Last updated: 2026-10-13T20:13:16Z

- Published: 2026-10-08 19:03 UTC · Updated: 2026-10-13 20:13 UTC · Assigner: mongodb
- CVSS: 4.8 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
- EPSS: 0.26%, 17th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-252

## 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 vendors and products

- MongoDB: PHP Driver

## Tracked companies

- [MongoDB Atlas](https://rewindex.com/company/mongodb-atlas.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-106436)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-106436)
- [https://jira.mongodb.org/browse/PHPC-2739](https://jira.mongodb.org/browse/PHPC-2739)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-106436 · Markdown: https://rewindex.com/cve/CVE-2026-106436.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-106436 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:13:11.858Z