Mongodb C Driver
CVE-2026-84963
An incorrect numeric conversion in the JSON parsing component of the MongoDB C Driver's BSON library may cause an unusually large text value to be silently shortened, or the corresponding field to be omitted, while the parsing operation still reports success and returns no error. An unauthenticated party who can supply the input processed by an application that uses this component may cause that application to hold data that does not match what was submitted, which may result in unintended alteration of data.
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 remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 8% 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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Tell us where you run Mongodb C Driver and a Fastnexa penetration tester will check whether this flaw, or others like it, can be used against your websites, apps and network.
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Scoring
- CVSS
- 5.3 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N- CVSS v4
- 6.3
- Weakness
- CWE-681
- 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.