Quick answers
- Is CVE-2026-106437 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-106437 being exploited in the wild.
- How severe is CVE-2026-106437?
- Medium severity, with a CVSS score of 6.2, published 8 October 2026.
- Which products and versions are affected?
- MongoDB C Driver before 2.5.6 and before 1.30.13.
- Is there a fix for CVE-2026-106437?
- Yes: fixed in C Driver 2.5.6, 1.30.13. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-106437 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-106437?
- Check whether you run MongoDB C Driver at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: C Driver 2.5.6, 1.30.13
Technical details
The bson_reserve_buffer API does not enforce the five-byte BSON minimum length requirement, permitting a caller to reserve a buffer smaller than spec. Subsequent append or comparison operations perform unsigned arithmetic on the length field, causing buffer underflow and out-of-bounds reads or writes. This requires the embedding application to pass user-controlled or insufficiently validated data as the length parameter to the vulnerable function.
Affected products
- MongoDB C Driver before 2.5.6 and before 1.30.13
Timeline
- 2026-10-08: disclosed