Vulnerability · Published Oct 22, 2026 · Assigned by mongodb
CVE-2026-114655KMS request injection via unsanitized key vault and provider values in libmongocrypt
Medium 5.9
In plain English
A medium-severity injection in libmongocrypt from MongoDB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
libmongocrypt builds requests to external key management services (AWS, Azure and GCP) by inserting values from key vault documents, KMS provider configuration and KMS responses into request lines, headers and signed request bodies without validating or encoding them for each context. A user with write access to the key vault collection can alter the structure of these requests, including adding members to request bodies and token claims that the library then signs with the application's credentials. This may result in key management operations being performed with parameters the application did not intend.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libmongocrypt | no fix listed | DEBIAN-CVE-2026-114655 |
| Debian:13 | libmongocrypt | no fix listed | DEBIAN-CVE-2026-114655 |
| Debian:14 | libmongocrypt | 1.21.1-1 | DEBIAN-CVE-2026-114655 |
| Ubuntu:22.04:LTS | libmongocrypt | no fix listed | UBUNTU-CVE-2026-114655 |
| Ubuntu:24.04:LTS | libmongocrypt | no fix listed | UBUNTU-CVE-2026-114655 |
| Ubuntu:26.04:LTS | libmongocrypt | no fix listed | UBUNTU-CVE-2026-114655 |
| Ubuntu:26.10 | libmongocrypt | no fix listed | UBUNTU-CVE-2026-114655 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| MongoDB | libmongocrypt | 1.0.0 – before 1.21.1 |
Weakness: CWE-74 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N