CVE-2026-8853

Description

The MW WP Form plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'memo' parameter in all versions up to, and including, 5.1.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with editor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Because the memo value is stored via update_post_meta() rather than wp_insert_post(), WordPress's built-in kses and unfiltered_html protections do not apply, allowing attackers to break out of the textarea element via injected closing tags regardless of role-based content filtering.

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CVSS v3.1 Score

4.4

MEDIUM

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

EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.10%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://plugins.trac.wordpress.org/browser/mw-wp-form/tags/5.1.0/classes/controllers/class.contact-data.php#L134 https://plugins.trac.wordpress.org/browser/mw-wp-form/tags/5.1.0/templates/contact-data/detail.php#L77 https://plugins.trac.wordpress.org/browser/mw-wp-form/tags/5.1.3/classes/controllers/class.contact-data.php#L134 https://plugins.trac.wordpress.org/browser/mw-wp-form/tags/5.1.3/templates/contact-data/detail.php#L77 https://plugins.trac.wordpress.org/changeset?old_path=mw-wp-form/tags/5.1.3&new_path=mw-wp-form/tags/5.1.4 https://www.wordfence.com/threat-intel/vulnerabilities/id/2a6dfdec-c1c6-4300-ab0a-9fd1c550d09f?source=cve

Frequently Asked Questions

What is CVE-2026-8853? +

The MW WP Form plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'memo' parameter in all versions up to, and including, 5.1.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with editor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Because the memo value is stored via update_post_meta() rather than wp_insert_post(), WordPress's built-in kses and unfiltered_html protections do not apply, allowing attackers to break out of the textarea element via injected closing tags regardless of role-based content filtering. It has a CVSS v3.1 base score of 4.4 (MEDIUM).

How severe is CVE-2026-8853? +

CVE-2026-8853 has a CVSS v3.1 score of 4.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-8853? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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