Out-of-bounds Read in MongoDB

CVE-2026-82066

A heap out-of-bounds read security issue exists in the query planning component of MongoDB Server. An authenticated user with database read and write privileges can trigger the security issue through crafted query operations, causing the server to read memory beyond allocated buffer boundaries. The revealed memory contents may be partially observable through diagnostic query statistics output.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (31.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-82066: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-82066?
CVE-2026-82066 is a medium-severity vulnerability in MongoDB, classified under Out-of-bounds Read. CVSS score: 4.3/10. Published 2026-09-08.
How severe is CVE-2026-82066?
Medium severity. CVSS v3 base score is 4.3 out of 10.