Mongodb C Driver
CVE-2026-84965
An integer wraparound in an allocation size calculation in the BSON library's JSON parsing code can cause a buffer to be released while a following copy operation still writes through the stale pointer. On builds where sizes are 32 bits, an unauthenticated party able to supply a sufficiently large JSON input to an application that links the library may cause that application to terminate unexpectedly, resulting in denial of service.
What this means for your business
- It affects Mongodb C Driver. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it only with access to the machine itself, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a less than 0.1% chance of attack attempts being seen in the next 30 days, ranking above 0% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Mongodb C Driver, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Fastnexa security experts
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Scoring
- CVSS
- 5.1 (v3.1)
- Vector
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H- CVSS v4
- 5.9
- Weakness
- CWE-190
- Assigned by
- cna@mongodb.com
Dates
- Published
- 2026-09-03
- Last modified
- 2026-09-22
- Sources
- NVD
Affected products
- Mongodb C Driver1.10.0 - 1.30.9, 2.0.0 - 2.5.2
As listed in the NVD configuration data. Not a statement about your estate.