# CVE-2026-106435: Application denial of service via out-of-bounds read in BSON Regex decoding in MongoDB Python Driver

> CVE-2026-106435: Application denial of service via out-of-bounds read in BSON Regex decoding in MongoDB Python Driver. CVSS 5.1 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-106435
Last updated: 2026-10-15T17:00:36Z

- Published: 2026-10-08 20:12 UTC · Updated: 2026-10-15 17:00 UTC · Assigner: mongodb
- CVSS: 5.1 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.09%, 1th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-125

## Description

The MongoDB Python Driver's binary accelerator can read outside a buffer when an application decodes malformed BSON containing a truncated regular-expression element without a trailing NUL byte. An actor who can supply BSON to the documented decode or decode\_all API can cause the application process to terminate when the C extension is loaded. The driver's normal database wire-protocol path does not reach this code.

## Affected vendors and products

- MongoDB: Python 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-2026-106435)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-106435)
- [https://jira.mongodb.org/browse/PYTHON-6110](https://jira.mongodb.org/browse/PYTHON-6110)

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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-2026-106435 · Markdown: https://rewindex.com/cve/CVE-2026-106435.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-106435 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:58.768Z