CVE-2020-20136

CRITICALNVD 9.89.8—

9.8

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.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 55.8%
KEV: Not listed

Published

December 14, 2020

Last Modified

November 21, 2024

References (2)

cve@mitrehttps://github.com/QuantConnect/Lean/issues/3537
af854a3a-2127-422b-91ae-364da2661108https://github.com/QuantConnect/Lean/issues/3537

Patch Availability(1)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
nuget	QuantConnect.Common	—	ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)

NuGet(1)

Package	Vulnerable range	Fixed in	Dependents
QuantConnect.Common	2.4.0.1-unofficial	—	—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-502Deserialization of Untrusted Data

Data Freshness Timeline

(refreshed 11× in last 7d / 19× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-02 20:11 UTCepss_batch
2026-06-02 20:11 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-06-01 13:50 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 22:29 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-31 00:15 UTCepss_batch
2026-05-29 13:42 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-28 13:43 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-24 16:48 UTCepss_batch
2026-05-23 04:16 UTCEG score recompute
2026-05-23 04:16 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2020-20136?

CVE-2020-20136 is a critical vulnerability published on December 14, 2020. 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.

When was CVE-2020-20136 disclosed?

CVE-2020-20136 was first published in the National Vulnerability Database on December 14, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2020-20136 actively exploited?

CVE-2020-20136 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 55.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2020-20136?

CVE-2020-20136 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2020-20136?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-20136, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-20136

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CVE-2020-20136

📅 Published

🔄 Last Modified

🔗 References (2)