CVE-2026-6691
Fixed in a distro release EPSS <1%CVSS 7.8
The MongoDB C Driver's Cyrus SASL integration performs unsafe string copying during username canonicalization, enabling a heap buffer overflow before any authentication or network traffic. This may be triggered by passing untrusted input in the username of a MongoDB URI with authMechanism=GSSAPI.
Products: MongoDB Inc. MongoDB C# Driver
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | mongo-c-driver | 1.23.1-1+deb12u3 |
| Debian 13 | mongo-c-driver | 1.30.4-1+deb13u2 |
| Debian 14 | mongo-c-driver | 2.2.0-1 |
| Ubuntu 25.10 | mongo-c-driver | no fix |
| Ubuntu Pro 20.04 LTS | mongo-c-driver | no fix |
| Ubuntu Pro 22.04 LTS | mongo-c-driver | no fix |
| Ubuntu Pro 24.04 LTS | mongo-c-driver | no fix |