CVE-2026-106429
Application denial of service via malformed KMS endpoint in MongoDB libmongocrypt
MongoDB libmongocryptDatabasesCVSS
7.1HighExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.29%Chance of exploitation activity in the next 30 days, higher than 20% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 1.20.5libmongocryptCVE List
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 integer underflow in the KMS endpoint-parsing logic of MongoDB libmongocrypt can cause an allocation failure that terminates the application process. This can occur when an authenticated user modifies a key document in the key vault collection, or when an application accepts a KMS endpoint containing a colon after its path or query during key creation. The issue does not access memory outside its allocated bounds.
Text from CVE List
Affected versions 1
- libmongocryptaffected: 1.1.0 before 1.20.5CVE List