Description
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
Score: 7.5 High
EPSS: n/a
KEV: No
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Remediation

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History

Tue, 10 Nov 2026 20:15:00 +0000

Type Values Removed Values Added
Description 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.
Title Privilege escalation via fail-open user lookup in X.509 cluster-membership guard
Weaknesses CWE-754
References
Metrics cvssV3_1

{'score': 6.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 7.5, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: mongodb

Published:

Updated: 2026-11-10T20:06:29.243Z

Reserved: 2026-11-02T22:54:17.417Z

Link: CVE-2026-120807

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-10T20:18:51.033

Modified: 2026-11-10T20:18:51.033

Link: CVE-2026-120807

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-754

    Improper Check for Unusual or Exceptional Conditions