Incorrect Conversion between Numeric Types in MongoDB driver for C - CVE-2026-84963

 

Incorrect Conversion between Numeric Types in MongoDB driver for C - CVE-2026-84963

Published: September 7, 2026


Vulnerability identifier: #VU147245
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-84963
CWE-ID: CWE-681
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to alter data.

The vulnerability exists due to incorrect numeric conversion in the JSON-to-BSON parser when processing unusually large JSON string values. A remote attacker can supply crafted JSON input to alter data.


Affected software

MongoDB driver for C
Fedora
mongo-c-driver

How to mitigate CVE-2026-84963

Install security update from vendor's website.

MongoDB driver for C - addressed in versions 1.30.9, 2.5.2
mongo-c-driver - addressed in versions 1.30.9-1.el8, 1.30.9-1.el9, 1.30.9-1.el10_2, 1.30.9-1.fc43, 1.30.9-1.fc44, 2.5.2-1.el10_3, 2.5.2-1.el10_4, 2.5.2-1.fc45

External References

Related Security Bulletins