What’s Vulnerable › Vulnerabilities
CVE-2026-106437: Out-of-bounds read and write via undersized BSON buffer reservation in MongoDB C Driver
- Severity: high (CVSS 7.4 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.1% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-10-08 · updated 2026-10-27
- Weakness: CWE-191
Description
The BSON buffer-reservation API in the MongoDB C Driver can record a length smaller than the five-byte BSON minimum. Later append or comparison operations can underflow unsigned length calculations and read or write outside the document buffer. An actor who can influence the length supplied by an embedding application can cause the application to terminate or read or corrupt adjacent process memory. Reaching this issue requires the application to pass an undersized value to bson_reserve_buffer and then perform an affected operation.
Affected products
- MongoDB C# Driver: from 1.4.0 before 1.30.13; from 2.0.0 before 2.5.6 — fixed in 1.30.13, 2.5.6
- MongoDB C# Driver: from 1.4.0 before 1.30.13; from 2.0.0 before 2.5.6 — fixed in 1.30.13, 2.5.6
How to fix
Upgrade to a fixed version: MongoDB C# Driver 1.30.13, 2.5.6; MongoDB C# Driver 1.30.13, 2.5.6. Check the vendor advisory for mitigations.
References
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