MongoDB up to 8.3.15/9.0.6 SBE Window Function Accumulator use after free

Summaryinfo

A vulnerability classified as critical was found in MongoDB up to 8.3.15/9.0.6. This impacts an unknown function of the component SBE Window Function Accumulator. Such manipulation leads to use after free. This vulnerability is referenced as CVE-2026-120803. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, has been found in MongoDB up to 8.3.15/9.0.6. Affected by this issue is an unknown function of the component SBE Window Function Accumulator. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A use-after-free issue exists in MongoDB’s SBE (Slot-Based Execution) implementation of a window function accumulator used by certain $setWindowFields aggregation pipelines. Under specific conditions, the accumulator can retain a dangling pointer to memory that has since been freed. When this stale pointer is later dereferenced during serialization of the carried-forward value, it can result in a heap out-of-bounds read that may expose adjacent heap contents and crash the mongod server. An authenticated user with readWrite privileges on a database can trigger this issue by crafting a specific aggregation pipeline.

The advisory is available at jira.mongodb.org. This vulnerability is handled as CVE-2026-120803 since 11/02/2026. The exploitation is known to be easy. The attack may be launched remotely. The technical details are unknown and an exploit is not available.

Upgrading to version 8.3.16 or 9.0.7 eliminates this vulnerability.

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Productinfo

Type

• Database Software

Name

• MongoDB

Version

• 8.3.0
• 8.3.1
• 8.3.2
• 8.3.3
• 8.3.4
• 8.3.5
• 8.3.6
• 8.3.7
• 8.3.8
• 8.3.9
• 8.3.10
• 8.3.11
• 8.3.12
• 8.3.13
• 8.3.14
• 8.3.15
• 9.0.0
• 9.0.1
• 9.0.2
• 9.0.3
• 9.0.4
• 9.0.5
• 9.0.6

License

• open-source

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CPE 2.2info

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