# CVE-2026-106435: pymongo: The MongoDB Python Driver's binary accelerator can read outside a buffer when an application decodes malformed BSON c...

CVE-2026-106435 is fixed in pymongo on 1 platform by DEBIAN-CVE-2026-106435 (version 4.19.0-1), released October 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-106435
- Priority: Routine
- CVSS: 4.7 (medium)
- EPSS: 0.0009
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 8, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | pymongo Debian 14 | 4.19.0-1 | [DEBIAN-CVE-2026-106435](https://patchblox.com/security/data/fix/linux/debian-cve-2026-106435.md) | Oct 24, 2026 |

---

Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.