CVE-2021-40541
CWE-79Published: October 11, 2021· Updated: Jun 17, 2026
Official Description
PHPFusion 9.03.110 is affected by cross-site scripting (XSS) in the preg patterns filter html tag without "//" in descript() function An authenticated user can trigger XSS by appending "//" in the end of text.
Technical Analysis
CVE-2021-40541 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.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (2)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-40541 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts