CVE-2020-28478Public exploitNetwork attack vector

Object prototype modification via unsafe recursive merge

Published Jan 19, 2021 · Updated Sep 16, 2024

Prototype pollution in GreenSock GSAP before 3.6.0 allows remote attackers to modify inherited object properties through crafted configuration data. The _mergeDeep helper recursively assigns enumerable keys from gsap.config() or gsap.defaults() input without rejecting proto, constructor, or prototype. Exploitation requires a consuming application to pass attacker-controlled nested configuration data; the resulting prototype contamination can disrupt that JavaScript process or browser page.

CVSS severity7.5
High
EPSS probability1.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in GreenSock GSAP before 3.6.0 allows remote attackers to modify inherited object properties through crafted configuration data. The _mergeDeep helper recursively assigns enumerable keys from gsap.config() or gsap.defaults() input without rejecting proto, constructor, or prototype. Exploitation requires a consuming application to pass attacker-controlled nested configuration data; the resulting prototype contamination can disrupt that JavaScript process or browser page.

The record

CVE
CVE-2020-28478
Published
Jan 19, 2021
Updated
Sep 16, 2024
Vendor
GreenSock
Product
GSAP
Classifications
CWE-400, CWE-1321
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 19, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record 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=unspecified <3.6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GreenSock · GSAPversion=unspecified <3.6.0

Published CVSS scores

7.5SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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