All vulnerabilities
CVE-2026-106438

Silent Decimal128 value corruption via incorrect exactness check in MongoDB C Driver

MongoDB C DriverDatabases
Open in ThreatlineRecord JSON
CVSS
5.1Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.11%Chance of exploitation activity in the next 30 days, higher than 1% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in1.30.13Also 2.5.6CVE List
Published8 Oct 2026Updated 8 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

An incorrect calculation in Decimal128 string parsing in the MongoDB C Driver can accept certain over-precision inputs containing leading zeros instead of rejecting them. This produces a value different from the supplied text. An actor who can provide a decimal string to an embedding application, including through Extended JSON parsing, can cause the application to store or use an incorrect numeric value.

Text from CVE List

Affected versions 2

  • C Driveraffected: 1.4.0 before 1.30.13CVE List
  • C Driveraffected: 2.0.0 before 2.5.6CVE List

References 1