CVE-2023-28103Network attack vector

Denial of service via prototype pollution

Published Mar 28, 2023 · Updated Feb 18, 2025

Prototype pollution in Matrix.org matrix-react-sdk before 3.69.0 allows remote attackers to disrupt clients via crafted Matrix events. The public advisory names no function; event-data processing accepts special strings in key locations that modify Object.prototype. A client must use an affected configuration and process an event from a remote server; denial of service is demonstrated, while further logic effects are unspecified.

CVSS severity8.2
High
EPSS probability0.71%
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 Matrix.org matrix-react-sdk before 3.69.0 allows remote attackers to disrupt clients via crafted Matrix events. The public advisory names no function; event-data processing accepts special strings in key locations that modify Object.prototype. A client must use an affected configuration and process an event from a remote server; denial of service is demonstrated, while further logic effects are unspecified.

The record

CVE
CVE-2023-28103
Published
Mar 28, 2023
Updated
Feb 18, 2025
Vendor
Matrix.org
Product
matrix-react-sdk
Classifications
CWE-1321, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 28, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 18, 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=< 3.69.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Matrix.org · matrix-react-sdkversion=< 3.69.0

Published CVSS scores

8.2GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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