# CVE-2026-106438: mongo-c-driver: An incorrect calculation in Decimal128 string parsing in the MongoDB C Driver can accept certain over-precision input...

CVE-2026-106438 is fixed in mongo-c-driver on 1 platform by DEBIAN-CVE-2026-106438 (version 2.5.6-1), released October 16, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-106438
- Priority: Routine
- CVSS: 3.7 (low)
- EPSS: 0.0014
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 8, 2026

## Description

An incorrect calculation in Decimal128 string parsing in the MongoDB C Driver can accept certain over-precision inputs containing leading zeros instead of rejecting them. This produces a value different from the supplied text. An actor who can provide a decimal string to an embedding application, including through Extended JSON parsing, can cause the application to store or use an incorrect numeric value.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | mongo-c-driver Debian 14 | 2.5.6-1 | [DEBIAN-CVE-2026-106438](https://patchblox.com/security/data/fix/linux/debian-cve-2026-106438.md) | Oct 16, 2026 |

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Data as of 2026-11-10T01:44:33Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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