MongoDBDatabase / datastore
CVE-2026-1850
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 · uneditedComplex queries can cause excessive memory usage in MongoDB Query Planner resulting in an Out-Of-Memory Crash.
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 confidenceThis is a denial-of-service vulnerability in MongoDB's Query Planner where complex queries consume excessive memory, potentially leading to an Out-Of-Memory crash. The vulnerability is triggered by specially crafted complex queries that cause the query planner to allocate excessive memory during query planning phase.
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
>= 8.0.0, < 8.0.18>= 8.2.0, < 8.2.4CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify installed MongoDB versionRun 'db.version()' in the mongo shell or use 'mongod --version' from command line to retrieve the exact version numberAffected if The installed version falls within >= 8.0.0 and < 8.0.18, OR >= 8.2.0 and < 8.2.4
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Review query patterns for complexityExamine application queries, particularly those with multiple $or clauses, deep nested $and/$or structures, or large $in arrays. Use the MongoDB profiler (db.setProfilingLevel(2)) to capture slow queries and analyze their structureAffected if Complex queries with extensive boolean logic, large IN clauses, or deeply nested conditions are being executed against the database
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Monitor for memory pressure during query planningCheck MongoDB logs for entries indicating excessive memory allocation during query planning, or monitor system memory usage during periods of complex query executionAffected if Logs show query planner memory allocation failures or the database experiences elevated memory consumption correlated with complex query operations
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Check for Out-Of-Memory eventsReview MongoDB log files (default location /var/log/mongodb/) for OOM crash indicators or restart events coinciding with complex query executionAffected if The database has experienced OOM crashes or unexpected restarts that cannot be attributed to other causes
Your environment is affected if you run MongoDB version 8.0.0-8.0.17 or 8.2.0-8.2.3 AND execute complex queries that cause the query planner to consume excessive memory.
Generated from the published advisory. Verify against your own configuration.
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 · scoped8.0.188.2.4
Implement query complexity limits and timeouts at the application and database level. Monitor query patterns and optimize or block queries that exhibit excessive memory consumption characteristics. Apply vendor patches when available.
MongoDB 8.0.18 or 8.2.4 (depending on your current minor branch)
- Determine your current MongoDB version using: db.version()
- Plan maintenance window for upgrade (requires restart)
- Backup all databases before upgrading
- For MongoDB 8.0.x: Upgrade to version 8.0.18 or later
- For MongoDB 8.2.x: Upgrade to version 8.2.4 or later
- Follow official MongoDB upgrade instructions for your deployment type (standalone/replica set/sharded cluster)
- Restart MongoDB service after package installation
- Verify upgrade success by checking: db.version()
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in MongoDB
Scoped from the published advisory
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,680.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-1850 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-1850 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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