CVE-2026-9748 $_internalConvertBucketIndexStats may crash the mongod server when working on no timeseries input
A crafted aggregation pipeline can crash the MongoDB server by triggering an assertion failure in the TeeBuffer component.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-9748?
CVE-2026-9748 is a high-severity denial of service vulnerability in Mongodb Mongodb, published on 9 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-617
Which versions are affected by CVE-2026-9748?
1 open source package ship an affected version, including mongodb. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mongodb Bitnami | From 7.0.0 | 7.0.35, 8.0.10, 8.2.10, 8.3.3 |
Products include Mongodb Mongodb.
How do I fix CVE-2026-9748?
Upgrade mongodb to a fixed version for your release line: 7.0.35, 8.0.10, 8.2.10 or 8.3.3.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-9748 being exploited?
There is no known exploitation of CVE-2026-9748 in the wild and no public exploit code.
Other vulnerabilities in Mongodb Mongodb
- CVE-2025-14847 MongoDB and MongoDB Server Improper Handling of Length Parameter Inconsistency
- CVE-2026-82067 Auth bypass in MongoDB Server
- CVE-2026-13072 MongoDB Improper Input Validation in Compute Mode External Data Processing Leading to Memory Corruption
- CVE-2017-15535 Denial of service in n/a
- CVE-2026-18691 Improper Authentication in MongoDB Intra-Cluster Connections Allows Credential Exposure
Sources
Also known as BIT-mongodb-2026-9748, GHSA-7r4j-g3f5-3629, MINI-882v-6wc2-vffw, MINI-f74v-9mpx-j27j, MINI-h9g7-rgrj-gvm8, MINI-hwp5-fq4q-wq75 and 1 more.