Denial of service in MongoDB Server mongos via crafted pipeline
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-617.
Summary
MongoDB Server from 8.3.0 before 8.3.13 and from 9.0 before 9.0.4 is affected. An internal aggregation stage lacks authorization checks, so a later stage runs on the mongos router in a state it was not designed to handle, causing an unhandled fatal error (CWE-617). An authenticated user with readWrite privileges can crash the mongos process with a specially formed aggregation pipeline, denying service to all clients routed through that instance.
Written with Claude Haiku 5.5 from the sources below · 2026-10-27
Description from the CNA
A security issue was discovered in MongoDB mongos (the sharded cluster router) where an authenticated user with readWrite privileges could crash the mongos process by crafting a specially formed aggregation pipeline. The issue leverages an internal aggregation stage that lacks proper authorization checks despite being intended for internal use, allowing a subsequent stage to be forced to execute on the router under conditions it was not designed to handle. This results in an unhandled fatal error that causes the mongos process to immediately abort, resulting in denial of service for all clients routed through the affected mongos instance.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade MongoDB Server to version 8.3.13 or 9.0.4, whichever matches the installed release line.
Written with Claude Haiku 5.5 from the sources below · 2026-10-27
- Fix · CNA MongoDB Server (MongoDB) Fixed in 8.3.13, 9.0.4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
MongoDB Server 8.3.13, 9.0.4
2 records Highest priority Priority LOW 2 LOW
Other records, highest priority first
- TI-2026-71816 Missing authorization check in MongoDB mongos enables denial of servicePriority LOW 31
Timeline
- 2026-10-13 Threatist record created from CVE-2026-104005
- 2026-10-13 CVSS score changed · CNA
- 2026-10-13 Weakness changed · CNA
- 2026-10-13 Priority changed: LOW → MEDIUM
- 2026-10-13 Alias added: GHSA-56w2-wpqh-pq52
- 2026-10-14 Priority changed: MEDIUM → LOW
- 2026-10-16 CISA SSVC decision points changed
References
More MongoDB vulnerabilities
- TI-2019-08023 Code injection in mongo-express KEVCVSS 3.1CRITICAL 9.9
- TI-2025-13542 Zlib compressed protocol header length confusion may allow memory read KEVCVSS 4.0HIGH 8.7
- TI-2026-79432 BSON output corruption via out-of-range binary subtype in MongoDB C# Driver CVSS 4.0MEDIUM 6.9
- TI-2026-79424 NoSQL command injection via mismatched BSON length in MongoDB C# Driver CVSS 4.0MEDIUM 6.9
- TI-2026-79422 Unbounded memory growth in MongoDB C# Driver BSON deserialization CVSS 4.0HIGH 8.2
- TI-2026-79427 Authentication bypass via issuer-and-serial-only certificate equality CVSS 4.0HIGH 7.6
Sources
- CVE-2026-104005 · CVE Program
- CVE-2026-104005 · NVD
- FIRST EPSS
- GHSA-56w2-wpqh-pq52 · GitHub Advisory Database · CC BY 4.0
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