CVE-2026-84963 PUBLISHED

Silent field truncation via unchecked int cast of huge JSON string values in JSON-to-BSON parser

Assigner: mongodb
Reserved: 02.09.2026 Published: 03.09.2026 Updated: 03.09.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS Score: 6.3

Product Status

Vendor MongoDB
Product C Driver
Versions Default: unaffected
  • affected from 1.10.0 to 1.30.9 (excl.)
  • affected from 2.0.0 to 2.5.2 (excl.)

References

Problem Types

  • CWE-681: Incorrect Conversion between Numeric Types CWE