# CVE-2026-88034: MongoDB C++ Driver GridFS injection in file identifier query

Source: https://junglewise.ai/threats/cve-2026-88034-mongodb-c-driver-gridfs-injection-in-file-identifier-query  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-10. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-88034 · Severity: high · CVSS 8.3 · Published 2026-09-10

The MongoDB C++ Driver's GridFS component, which handles large file storage within MongoDB databases, contains a flaw that allows user-supplied file identifiers to be interpreted as database queries rather than literal values. An authenticated attacker who controls the file identifier used by an application could read files outside the intended scope or delete all file chunks in a storage bucket, rendering stored data inaccessible and potentially causing data loss.

Technologies: [MongoDB C Driver](https://junglewise.ai/threats/technologies/c-driver). Vendors: [MongoDB](https://junglewise.ai/threats/vendors/mongodb).

## Quick answers

**Is CVE-2026-88034 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-88034 being exploited in the wild.

**How severe is CVE-2026-88034?** High severity, with a CVSS score of 8.3, published 10 September 2026.

**Which products and versions are affected?** MongoDB C Driver before 4.5.3.

**Is there a fix for CVE-2026-88034?** A patch was published on 2026-09-11: Fix released in version 4.5.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-88034 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-88034?** Check whether you run MongoDB C Driver at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an improper neutralization of special elements in data query logic (CWE-89 equivalent, injection-style flaw) in the GridFS component of the MongoDB C++ Driver. The root cause is that user-supplied file identifiers are not properly escaped or explicitly matched using query operators; they are concatenated into database query conditions, allowing attackers to inject MongoDB query syntax. An authenticated user with the ability to influence the file ID parameter passed to GridFS methods can exploit this to either retrieve unintended file content or delete file chunks across the bucket. The fix, available in version 4.5.3, implements explicit exact-match queries using the $eq operator for all user-supplied GridFS file IDs in database commands.

## Affected products

- MongoDB C++ Driver before 4.5.3

## Timeline

- 2026-09-10: disclosed
- 2026-09-11: patched: Fix released in version 4.5.3

## References

- [https://jira.mongodb.org/browse/CXX-3556](https://jira.mongodb.org/browse/CXX-3556)

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