CVSS 4.0
6.1 mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:NCVE-2026-120809 Heap use-after-free read via yield-time state save in time-series block unpacking
Medium (6.1) in mongodb mongodb server. EPSS 0.4% estimated probability of exploitation activity in the next 30 days.
A use-after-free read issue exists in MongoDB’s SBE (Slot-Based Execution) engine when processing aggregation pipelines with $unwind on time-series collections. An internal error in state-preservation logic can cause a value still referenced by downstream stages to have its underlying memory freed prematurely. An authenticated user can craft an aggregation pipeline under specific conditions to trigger this condition, potentially reading recycled server heap memory in query results or crashing the server. This issue is only triggerable when a non-default server parameter related to the SBE engine is enabled.
Severity
CVSS 3.1
6.8 mediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/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 |
| MongoDB Server | from 8.0.0 before 8.0.37 |