CVE-2026-9748

The $_internalConvertBucketIndexStats stage used PauseExecution as a way to signal "skip this document" when an index stats conversion failed. But PauseExecution is not a general purpose skip mechanism, but rather a TeeBuffer-internal signal used solely by $facet to coordinate its sub-pipelines. When this stage is placed before $facet in a pipeline, TeeBuffer receives the unexpected PauseExecution from upstream and hits a hard invariant assertion, crashing mongod.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://jira.mongodb.org/browse/SERVER-123951	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mongodb:mongodb::::::::
	cpe:2.3:a:mongodb:mongodb::::::::
	cpe:2.3:a:mongodb:mongodb::::::::
	cpe:2.3:a:mongodb:mongodb::::::::

History

23 Jul 2026, 09:10

Type	Values Removed	Values Added
Summary		(es) La etapa $_internalConvertBucketIndexStats usó PauseExecution como una forma de señalar 'saltar este documento' cuando fallaba una conversión de estadísticas de índice. Pero PauseExecution no es un mecanismo de salto de propósito general, sino más bien una señal interna de TeeBuffer utilizada únicamente por $facet para coordinar sus sub-tuberías. Cuando esta etapa se coloca antes de $facet en una tubería, TeeBuffer recibe el PauseExecution inesperado de upstream y alcanza una aserción invariante dura, colapsando mongod.

15 Jun 2026, 17:10

Type	Values Removed	Values Added
First Time		Mongodb mongodb Mongodb
References	~~() https://jira.mongodb.org/browse/SERVER-123951 -~~	() https://jira.mongodb.org/browse/SERVER-123951 - Vendor Advisory
CPE		cpe:2.3:a:mongodb:mongodb::::::::

09 Jun 2026, 23:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-09 23:17

Updated : 2026-07-23 09:10

NVD link : CVE-2026-9748

Mitre link : CVE-2026-9748

CVE.ORG link : CVE-2026-9748

JSON object : View

Products Affected

mongodb

mongodb

CWE

CWE-617

Reachable Assertion

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Cuando esta etapa se coloca antes de $facet en una tuber\u00eda, TeeBuffer recibe el PauseExecution inesperado de upstream y alcanza una aserci\u00f3n invariante dura, colapsando mongod."}], "lastModified": "2026-07-23T09:10:00.113", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4A597EDD-7227-4462-9742-EC211F3D3043", "versionEndExcluding": "7.0.35", "versionStartIncluding": "7.0.0"}, {"criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "CB0E4B87-D42B-446A-A8C3-51258076AFF2", "versionEndExcluding": "8.0.10", "versionStartIncluding": "8.0.0"}, {"criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F3BDF7B8-82C8-4F03-9614-6FD73582D174", "versionEndExcluding": "8.2.10", "versionStartIncluding": "8.2.0"}, {"criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "565AB85D-0F4A-4ED3-B951-7949D7AB85A6", "versionEndExcluding": "8.3.3", "versionStartIncluding": "8.3.0"}], "operator": "OR"}]}], "sourceIdentifier": "cna@mongodb.com"}