Cyber Posture

CVE-2025-26879

High

Published: 03 March 2025

Published
03 March 2025
Modified
29 April 2026
KEV Added
Patch
CVSS Score 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
EPSS Score 0.0021 42.8th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Description

An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.

Security Summary

CVE-2025-26879 is an Improper Neutralization of Input During Web Page Generation vulnerability, classified as Reflected Cross-site Scripting (XSS) under CWE-79, in the s2Member WordPress plugin developed by Cristián Lávaque. This issue affects s2Member versions from n/a through <= 241216. The vulnerability was published on 2025-03-03T14:15:56.213 and carries a CVSS v3.1 base score of 7.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L).

Attackers can exploit this vulnerability remotely over the network with low attack complexity and no required privileges, though it necessitates user interaction such as clicking a malicious link. Upon successful exploitation, adversaries achieve low impacts on confidentiality, integrity, and availability, with a changed scope that elevates the potential effects through the reflected payload, such as session hijacking or phishing within the context of affected WordPress sites.

The primary advisory from Patchstack, available at https://patchstack.com/database/Wordpress/Plugin/s2member/vulnerability/wordpress-s2member-plugin-241216-reflected-cross-site-scripting-xss-vulnerability?_s_id=cve, documents the Reflected XSS vulnerability in the s2Member plugin version 241216. Mitigation guidance emphasizes updating to a version beyond the affected range (<= 241216) to address the input neutralization flaw.

Details

CWE(s)
CWE-79

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
Why these techniques?

Reflected XSS in public-facing WordPress plugin directly maps to T1190 for initial exploitation of the web application; enables T1539 for stealing session cookies to achieve session hijacking as described in the impact.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References