# CVE-2026-114654: BSON output corruption via out-of-range binary subtype bypassing UUID and OldBinary guards

> CVE-2026-114654: BSON output corruption via out-of-range binary subtype bypassing UUID and OldBinary guards. CVSS 6.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-114654
Last updated: 2026-10-23T19:45:03Z

- Published: 2026-10-22 19:13 UTC · Updated: 2026-10-23 19:45 UTC · Assigner: mongodb
- CVSS: 6.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
- EPSS: 0.35%, 28th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-681

## Description

A numeric-type conversion flaw in the BSON handling library of the MongoDB C\# Driver allows an out-of-range binary subtype value supplied through untrusted textual input to bypass the library's binary-element integrity checks. When such a value is later encoded, it is narrowed to a smaller wire representation, producing binary elements that misdeclare their type or length. An unauthenticated party able to supply text parsed by an affected application can cause it to emit and persist malformed binary data, which subsequent readers either reject with an error or silently interpret as shorter than the data that was validated.

## Affected vendors and products

- MongoDB: C\# 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-2026-114654)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-114654)
- [https://github.com/mongodb/mongo-csharp-driver/releases/tag/v3.13.0](https://github.com/mongodb/mongo-csharp-driver/releases/tag/v3.13.0)
- [https://github.com/mongodb/mongo-csharp-driver/security/advisories/GHSA-5h2q-6c9r-7x25](https://github.com/mongodb/mongo-csharp-driver/security/advisories/GHSA-5h2q-6c9r-7x25)
- [https://jira.mongodb.org/browse/CSHARP-6166](https://jira.mongodb.org/browse/CSHARP-6166)

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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-2026-114654 · Markdown: https://rewindex.com/cve/CVE-2026-114654.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-114654 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:13:13.229Z