CVE-2026-120809
Heap use-after-free read via yield-time state save in time-series block unpacking
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| MongoDB Server MongoDB |
≥ 9.0.0; < 9.0.7 (affected, semver) ≥ 8.3.0; < 8.3.16 (affected, semver) ≥ 8.0.0; < 8.0.37 (affected, semver) Other versions: unaffected |
CNA: mongodb |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 6.1 medium |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N | CNA: mongodb |
| 3.1 / 6.8 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H | CNA: mongodb |
| 4.0 / 6.1 medium |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD: [email protected] |
| 3.1 / 6.8 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
For agents and automation
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