Vulnerability · Published Oct 22, 2026 · Assigned by mongodb
CVE-2026-114649Authentication bypass via issuer-and-serial-only certificate equality in shared cluster cache
Medium 6.8
In plain English
A medium-severity security flaw in C# Driver from MongoDB. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).
Official description
The MongoDB C# Driver compares TLS client certificates by issuer and serial number only when deciding whether two clients can share cached connections. In an application that creates clients from certificates supplied by different users, a user who provides a certificate copying another user's issuer and serial number, without that user's private key, can be given connections authenticated with the other user's certificate. Database operations can then run under the other user's identity, affecting the confidentiality and integrity of data that identity can access.
Affected products (as reported)
Weakness: CWE-1025 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N