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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.001 (0.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 0.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000
Affected products
Weakness classification (CWE)
References
- github.com/mongodb/libmongocrypt/releases/tag/1.20.3 (Product)
- jira.mongodb.org/browse/MONGOCRYPT-977 (Patch, Issue Tracking, Vendor Advisory)
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.