What is CVE-2026-120807?

CVE-2026-120807 is a medium-severity vulnerability in MongoDB Server, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 6.6/10. Published 2026-11-10.

How severe is CVE-2026-120807?

Medium severity. CVSS v3 base score is 6.6 out of 10.

Vulnerability in MongoDB Server

CVE-2026-120807

A flaw in MongoDB’s X.509 cluster-membership authentication guard could allow a holder of a cluster-member certificate to gain elevated internal privileges when a specific deployment configuration is in use. An internal check, which prevents a certificate recognized as a cluster member from also being treated as a regular user, does not correctly distinguish between certain error conditions encountered during user lookup. Under certain timing conditions, this can cause the check to be bypassed, granting the connection full internal system privileges. Triggering this issue requires possession of a valid cluster-member TLS certificate, non-default X.509 cluster authentication configuration, and specific conditions during the user cache lookup process.

Published 2026-11-10 · last modified 2026-11-10.

CVSS v3 metric

CVSS v3 base score 6.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

MongoDB Server

Weakness classification (CWE)

CWE-754 — Improper Check for Unusual or Exceptional Conditions

References

jira.mongodb.org/browse/SERVER-130169

Frequently asked questions

What is CVE-2026-120807?: CVE-2026-120807 is a medium-severity vulnerability in MongoDB Server, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 6.6/10. Published 2026-11-10.
How severe is CVE-2026-120807?: Medium severity. CVSS v3 base score is 6.6 out of 10.