CVE-2026-6691 Affecting mongo-c-driver package, versions <2.2.0-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIANUNSTABLE-MONGOCDRIVER-16325371
- published1 May 2026
- disclosed6 May 2026
Introduced: 1 May 2026
CVE-2026-6691 (opens in a new tab)How to fix?
Upgrade Debian:unstable mongo-c-driver to version 2.2.0-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream mongo-c-driver package and not the mongo-c-driver package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
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.