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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2026-120809- CVSS 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 - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H - Weakness
- CWE-416
- Updated
- 2026-11-10
EUVDEUVD-2026-122900
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.
- Record
EUVD-2026-122900- CVSS 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 - Updated
- 2026-11-11
GitHub AdvisoriesGHSA-3x8p-q9c8-5g87
A use-after-free read issue exists in MongoDB’s SBE (Slot-Based Execution) engine when processing...
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.
- Record
GHSA-3x8p-q9c8-5g87- CVSS 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 - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H - Weakness
- CWE-416
- Updated
- 2026-11-10
NVD
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.
- Record
CVE-2026-120809- CVSS 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 - CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H - Weakness
- CWE-416
- Updated
- 2026-11-10
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| published | EUVD | |
| published | EUVD | |
| products, severity, title | CVE List, NVD | |
| aliases, cwes, references, severity, title | GitHub Advisories | |
| first indexed | EUVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-120809 is a medium vulnerability (CVSS 6.1) in Mongodb Server, published November 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 31st percentile. No source names a fixed version.