Is CVE-2021-20293 actively exploited?

No active exploitation of CVE-2021-20293 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-20293 be exploited remotely?

Yes. CVE-2021-20293 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-20293?

CVE-2021-20293 has a CVSS score of 6.1 (MEDIUM).

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MEDIUM

CVE-2021-20293

CWE-79Published: June 10, 2021· Updated: Jun 17, 2026

6.1

CVSS v3.1

Official Description

A reflected Cross-Site Scripting (XSS) flaw was found in RESTEasy in all versions of RESTEasy up to 4.6.0.Final, where it did not properly handle URL encoding when calling @javax.ws.rs.PathParam without any @Produces MediaType. This flaw allows an attacker to launch a reflected XSS attack. The highest threat from this vulnerability is to data confidentiality and integrity.

NVD Source

Technical Analysis

CVE-2021-20293 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.