CVE-2026-96746 Heap buffer overflow via mid-scan command list growth in client topology monitoring
An attacker controlling DNS and host responses can trigger a heap buffer overflow in the MongoDB C Driver, causing application crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-96746?
CVE-2026-96746 is a high-severity memory corruption vulnerability in MongoDB C Driver, published on 24 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.
Weakness: CWE-787
Which versions are affected by CVE-2026-96746?
How do I fix CVE-2026-96746?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-96746 being exploited?
There is no known exploitation of CVE-2026-96746 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-96746, GHSA-frjf-h5jg-4v46, UBUNTU-CVE-2026-96746.