CVE-2021-32622

File upload local preview can run embedded scripts after user interaction

HIGH
7.8
CVSS Score
Published: May 17, 2021 at 07:35 PM UTC
Updated: June 17, 2026 at 03:53 AM UTC
2 products affected across 2 vendorsMatrix React SDKMatrix React SDK

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Severity
HIGH7.8
Exploit prediction
EPSS 0.4%

Description

Matrix-React-SDK is a react-based SDK for inserting a Matrix chat/voip client into a web page. Before version 3.21.0, when uploading a file, the local file preview can lead to execution of scripts embedded in the uploaded file. This can only occur after several user interactions to open the preview in a separate tab. This only impacts the local user while in the process of uploading. It cannot be exploited remotely or by other users. This vulnerability is patched in version 3.21.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.21.0
Affected range stops below 3.21.0, so it looks safe — our inference, not a vendor statement
v < 3.21.0
Affected range stops below 3.21.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-74CWE-434

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