CVE-2025-26879

Vulnerability

Overview

The s2Member WordPress plugin, versions up to and including 241216, suffers from a reflected cross-site scripting (XSS) vulnerability due to improper neutralization of user-supplied input during web page generation [1]. The flaw exists in the s2member plugin and is classified as CVE-2025-26879 with a CVSS v3 base score of 7.1 (High) [1].

Exploitation

Details

An attacker can exploit this vulnerability by crafting a malicious link or request that, when visited by a privileged user (such as an administrator), causes arbitrary JavaScript execution in the victim's browser [1]. User interaction is required; the victim must click a crafted link, visit a specially crafted page, or submit a form [1]. No authentication is needed to initiate the attack, but the target user must have elevated privileges to trigger execution.

Impact

Successful exploitation could allow an attacker to inject malicious scripts, including redirects, advertisements, or other HTML payloads that execute when visitors access the affected site [1]. This can lead to session hijacking, defacement, or other harmful actions performed in the context of the logged-in user's session.

Mitigation

The vulnerability is patched in version 250214 and later; users are strongly advised to update immediately [1]. A mitigation rule is available from Patchstack to block attacks until the update is applied [1]. Given that this vulnerability is expected to be used in mass-exploit campaigns, prompt remediation is critical [1].