# CVE-2026-84971

## Summary

- **CVE ID:** CVE-2026-84971
- **Severity:** HIGH
- **CVSS Score:** 7.1 (CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-617
- **Published:** Sep 3, 2026
- **Last Modified:** Sep 3, 2026

## Description

Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control the responses the application receives, may cause that application to stop running.

## Affected Products

- MongoDB — libmongocrypt (1.7.0)

## References

- [CNA](https://jira.mongodb.org/browse/MONGOCRYPT-971)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.16%
- **EPSS Percentile:** 5.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._