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MongoDBDatabase / datastore

CVE-2026-9748

MEDIUM · 6.5 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 7.0.35 / 8.0.10 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The $_internalConvertBucketIndexStats stage in MongoDB incorrectly uses PauseExecution as a skip mechanism for failed index stats conversions. PauseExecution is a TeeBuffer-internal signal meant only for $facet sub-pipeline coordination. When this stage precedes $facet in a pipeline, TeeBuffer receives an unexpected PauseExecution signal, triggering a hard invariant assertion that crashes mongod.

MitigationAvoid using $_internalConvertBucketIndexStats before $facet in aggregation pipelines until an official patch is available. Monitor for mongod crashes and review pipeline configurations.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MongoDBDatabase / datastore
Affected:>= 7.0.0, < 7.0.35>= 8.0.0, < 8.0.10>= 8.2.0, < 8.2.10>= 8.3.0, < 8.3.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check MongoDB server version
    Run db.version() in mongosh or execute: mongod --version
    Affected if The installed version falls within these ranges: 7.0.0-7.0.35, 8.0.0-8.0.10, 8.2.0-8.2.10, or 8.3.0-8.3.3
  2. Review aggregation pipeline logs for internal bucket stats stage
    Search application logs, MongoDB profiler output (db.setProfilingLevel(2)), or audit logs for occurrences of '$_internalConvertBucketIndexStats' in aggregation pipelines
    Affected if Any aggregation pipeline in your environment uses the $_internalConvertBucketIndexStats stage
  3. Check if $_internalConvertBucketIndexStats precedes $facet
    For each pipeline using $_internalConvertBucketIndexStats, verify the stage order: $_internalConvertBucketIndexStats must appear before $facet in the pipeline array
    Affected if A pipeline contains $_internalConvertBucketIndexStats immediately before or somewhere preceding a $facet stage
  4. Look for crash logs with invariant assertion
    Examine MongoDB log files (mongod.log) for entries containing 'invariant' 'PauseExecution' or 'TeeBuffer' combined with aggregation errors or process crashes
    Affected if MongoDB has crashed with an invariant assertion failure mentioning PauseExecution or TeeBuffer in the context of aggregation

You are affected if your MongoDB version is in the affected range AND you have aggregation pipelines using $_internalConvertBucketIndexStats before $facet, or you observe related crash logs.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 7.0.35 / 8.0.10 / 8.2.10 or later
Fixed in 7.0.358.0.108.2.10
Interim mitigation

Avoid using $_internalConvertBucketIndexStats before $facet in aggregation pipelines until an official patch is available. Monitor for mongod crashes and review pipeline configurations.

Recommended fix High confidence

7.0.35, 8.0.10, 8.2.10, or 8.3.3 (depending on your current major version branch)

  1. 1. Backup your MongoDB database before performing any upgrade
  2. 2. Ensure you have a valid backup and tested restoration procedure
  3. 3. For MongoDB 7.0.x: Upgrade to version 7.0.35 or later
  4. 4. For MongoDB 8.0.x: Upgrade to version 8.0.10 or later
  5. 5. For MongoDB 8.2.x: Upgrade to version 8.2.10 or later
  6. 6. For MongoDB 8.3.x: Upgrade to version 8.3.3 or later
  7. 7. After upgrade, verify mongod starts successfully and test that aggregation pipelines using $_internalConvertBucketIndexStats before $facet no longer crash
  8. 8. Monitor logs for any assertion failures to confirm the fix is effective
Caveat Upgrading MongoDB major versions may require reviewing application compatibility and running the database upgrade procedure; minor version upgrades within the same major version are generally safer

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in MongoDB Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-9748 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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