CVE-2021-20190Network attack vector

Remote code execution via incomplete gadget blacklist

Published Jan 19, 2021 · Updated Aug 27, 2025

Deserialization of untrusted data in FasterXML jackson-databind before 2.9.10.7 allows remote attackers to execute code via crafted JSON. SubTypeValidator omits the javax.swing.JTextPane gadget from its blocked subtype list, allowing polymorphic typing to instantiate a dangerous gadget during deserialization. Exploitation requires an application to deserialize attacker-controlled JSON with polymorphic typing enabled; successful chains can compromise confidentiality, integrity, and availability.

CVSS severity8.1
High
EPSS probability7.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization of untrusted data in FasterXML jackson-databind before 2.9.10.7 allows remote attackers to execute code via crafted JSON. SubTypeValidator omits the javax.swing.JTextPane gadget from its blocked subtype list, allowing polymorphic typing to instantiate a dangerous gadget during deserialization. Exploitation requires an application to deserialize attacker-controlled JSON with polymorphic typing enabled; successful chains can compromise confidentiality, integrity, and availability.

The record

CVE
CVE-2021-20190
Published
Jan 19, 2021
Updated
Aug 27, 2025
Vendor
FasterXML
Product
jackson-databind
Classifications
CWE-502
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=jackson-databind 2.9.10.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FasterXML · jackson-databindversion=jackson-databind 2.9.10.7

Published CVSS scores

8.1NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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