CVSS 4.0
7.1 highCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:NCVE-2026-120803 MongoDB SBE $locf Window Accumulator Use-After-Free Enables Heap OOB Read and Server Crash
High (7.1) in mongodb mongodb server. EPSS 0.4% estimated probability of exploitation activity in the next 30 days.
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.
Severity
CVSS 3.1
7.1 highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H- EPSS
- 0.4% estimated probability of exploitation activity in the next 30 days; 31st percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-416 Use After Free
- Published
- Modified
- Assigned by
- mongodb (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
- mongodb:mongodb server
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| MongoDB Server | from 9.0.0 before 9.0.7 |
| MongoDB Server | from 8.3.0 before 8.3.16 |