CVE-2025-26879

s2Member Pro <= 241216 - Reflected Cross-Site Scripting

2025-02-22 00:00

Strategic Overview

Status: Patched in 250214
Affected Plugin: s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions
Affected Version: <= 241216
CVSS: 6.1Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2025-26879

View all s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions vulnerabilities

At a glance

CVE-2025-26879 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the s2Member WordPress plugin, affecting versions <= 241216. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 250214; sites on affected versions should update now. Disclosed February 2025, reported by 0xd4rk5id3.

Vulnerability Overview

The s2Member Pro plugin for WordPress is vulnerable to Reflected Cross-Site Scripting in versions up to, and including, 241216 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in s2Member <= 241216 takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For s2Member the fix is 250214: builds <= 241216 are affected, anything from 250214 onward is not.

Remediation

Update to version 250214, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to s2Member: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: s2Member 250214 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2025-26879 https://www.wordfence.com/threat-intel/vulnerabilities/id/016c56c0-38d2-4f84-a0bc-3c6c25847603 https://nvd.nist.gov/vuln/detail/CVE-2025-26879

Related records

Same weakness class

Other vulnerabilities in s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions

CVSS Vector

6.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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