CVE-2026-84962
Description
A flaw was found in MONGOCRYPT. An unauthorized user with key vault write access could exploit this vulnerability to cause an authorized client to issue arbitrary authenticated Google Cloud KMS (Key Management Service) API calls. This could lead to privilege escalation, allowing the unauthorized user to gain elevated database-level access into cloud key control and defeat client-side encryption.
Statement
A flaw was found in libmongocrypt. An attacker with key vault write access can craft malicious data that causes an authorized MongoDB client to issue arbitrary authenticated Google Cloud KMS API calls under the victim's identity. This server-side request forgery vulnerability affects only configurations using Google Cloud KMS for client-side encryption.
Mitigation
Update to libmongocrypt 1.20.4 or later.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.2 | N/A | 4.2 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | High | N/A | High |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Access Control
Technical Impact: Bypass Protection Mechanism
By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
