What’s Vulnerable › Vulnerabilities

CVE-2026-81524: Cross-tenant database retargeting via dot/NUL injection in namespace strings in the C Driver

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-27 · updated 2026-09-29
• Weakness: CWE-99

Description

A weakness in the MongoDB C Driver allows special elements in caller-supplied database and collection name components to pass without sanitization when the driver composes the target namespace for an operation. An application that incorporates untrusted input into these name components can have operations directed at a resource other than the one intended.

Affected products

• MongoDB C# Driver: from 1.0.0 before 2.5.1 — fixed in 2.5.1

How to fix

Upgrade to a fixed version: MongoDB C# Driver 2.5.1. Check the vendor advisory for mitigations.

References

• https://github.com/mongodb/mongo-c-driver/releases/tag/2.5.1
• https://jira.mongodb.org/browse/CDRIVER-6424

Get alerted when CVE-2026-81524 or the next vulnerability affects your stack