What is CVE-2026-81523?

CVE-2026-81523 is a medium-severity vulnerability in MongoDB Libmongocrypt, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 4.4/10. Published 2026-08-27.

How severe is CVE-2026-81523?

Medium severity. CVSS v3 base score is 4.4 out of 10.

Vulnerability in MongoDB Libmongocrypt

CVE-2026-81523

A missing input-validation issue in MongoDB libmongocrypt's automatic-encryption context setup allows a caller-supplied database identifier to be accepted without sanitization. The resulting impact is limited to incorrect schema selection, which may lead to limited disclosure or modification of information handled by the application.

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

Affected products

Mongodb Libmongocrypt

Weakness classification (CWE)

CWE-74 — Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

References

Frequently asked questions

What is CVE-2026-81523?: CVE-2026-81523 is a medium-severity vulnerability in MongoDB Libmongocrypt, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 4.4/10. Published 2026-08-27.
How severe is CVE-2026-81523?: Medium severity. CVSS v3 base score is 4.4 out of 10.