CVE-2020-20136
QuantConnect Lean vulnerable to insecure deserialization
QuantConnect Lean versions from 2.3.0.0 to 2.4.0.1 are affected by an insecure deserialization vulnerability due to insecure configuration of TypeNameHandling property in Json.NET library.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
QuantConnect Lean versions from 2.3.0.0 to 2.4.0.1 are affected by an insecure deserialization vulnerability due to insecure configuration of TypeNameHandling property in Json.NET library.
- Record
CVE-2020-20136- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-502
- Updated
- 2026-11-02
CVE List No score
QuantConnect Lean versions from 2.3.0.0 to 2.4.0.1 are affected by an insecure deserialization vulnerability due to insecure configuration of TypeNameHandling property in Json.NET library.
- Record
CVE-2020-20136- Updated
- 2026-11-02
EUVDEUVD-2022-5652 No score
QuantConnect Lean versions from 2.3.0.0 to 2.4.0.1 are affected by an insecure deserialization vulnerability due to insecure configuration of TypeNameHandling property in Json.NET library.
- Record
EUVD-2022-5652- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-ww7r-278h-48mh
QuantConnect Lean vulnerable to insecure deserialization
QuantConnect Lean versions from 2.3.0.0 to 2.4.0.1 are affected by an insecure deserialization vulnerability due to insecure configuration of TypeNameHandling property in Json.NET library. One may avoid this issue by only running Lean in an environment where data provided is trusted.
- Record
GHSA-ww7r-278h-48mh- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
OSV
QuantConnect Lean versions from 2.3.0.0 to 2.4.0.1 are affected by an insecure deserialization vulnerability due to insecure configuration of TypeNameHandling property in Json.NET library.
- Record
CVE-2020-20136- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-ww7r-278h-48mh
QuantConnect Lean vulnerable to insecure deserialization
QuantConnect Lean versions from 2.3.0.0 to 2.4.0.1 are affected by an insecure deserialization vulnerability due to insecure configuration of TypeNameHandling property in Json.NET library. One may avoid this issue by only running Lean in an environment where data provided is trusted.
- Record
GHSA-ww7r-278h-48mh- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
QuantConnect.CommonNuGet |
2.3.0.0 to 2.4.0.1 | None known |
QuantConnect.CommonNuGet |
2.3.0.0 to 2.4.0.1, plus listed versions 2.4.0.1-unofficial |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-20136 is a critical vulnerability (CVSS 9.8) in Quantconnect Lean, published December 14, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.54%, the 75th percentile. No source names a fixed version.