Is CVE-2021-36806 actively exploited?

No active exploitation of CVE-2021-36806 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-36806 be exploited remotely?

Yes. CVE-2021-36806 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-36806?

CVE-2021-36806 has a CVSS score of 6.1 (MEDIUM).

HOME VULNERABILITIESCVE-2021-36806

MEDIUM

CVE-2021-36806

CWE-79Published: November 30, 2023· Updated: Jun 17, 2026

6.1

CVSS v3.1

Official Description

A reflected XSS vulnerability allows an open redirect when the victim clicks a malicious link to an error page on

Sophos Email Appliance

older than version 4.5.3.4.

NVD Source

Technical Analysis

CVE-2021-36806 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.