What’s Vulnerable › Vulnerabilities
CVE-2026-88035: Heap buffer overflow via wrapped size check during SASL username canonicalization in MongoDB C Driver
- Severity: medium (CVSS 5.5 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: 2026-09-10 · updated 2026-09-16
- Weakness: CWE-190
Description
A size check in the client-side authentication path of the MongoDB C Driver can wrap around, so an unusually large user-name value is accepted and copied past the end of a small buffer. A party able to set the driver's connection settings may cause the application that embeds the driver to terminate unexpectedly. Reaching this code requires a build in which the optional external SASL authentication backend is present and a connection configured to use it.
Affected products
- MongoDB C# Driver: from 1.10.0 before 1.30.10; from 2.2.0 before 2.5.3 — fixed in 1.30.10, 2.5.3
How to fix
Upgrade to a fixed version: MongoDB C# Driver 1.30.10, 2.5.3. Check the vendor advisory for mitigations.
References
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