CVE-2026-6399: The General Options plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 1.1.0. This is due to the use of...

Description

The General Options plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 1.1.0. This is due to the use of sanitize_text_field() for output escaping in the Contact Number (ad_contact_number) field — a function that strips HTML tags but does not encode double-quote characters to their HTML entity equivalent ("). When the stored value is echoed inside a double-quoted HTML attribute (value="..."), an attacker-supplied double-quote character breaks out of the attribute context. Even with WordPress's wp_magic_quotes mechanism (which prefixes quotes with a backslash), the resulting \" sequence is NOT treated as an escaped quote by HTML parsers — the backslash is rendered as a literal character and the bare double-quote still closes the attribute. This makes it possible for authenticated attackers with Administrator-level access and above to inject arbitrary web scripts in the admin settings page that will execute whenever any administrator visits the General Options settings page.

Metrics

CVSS 3.1

4.4/10

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

EPSS Probability

0.23%

13.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: May 20, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-6399?

The General Options plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 1.1.0. This is due to the use of sanitize_text_field() for output escaping in the Contact Number (ad_contact_number) field — a function that strips HTML tags but does not encode double-quote characters to their HTML entity equivalent ("). When the stored value is echoed inside a double-quoted HTML attribute (value="..."), an attacker-supplied double-quote character breaks out of the attribute context. Even with WordPress's wp_magic_quotes mechanism (which prefixes quotes with a backslash), the resulting \" sequence is NOT treated as an escaped quote by HTML parsers — the backslash is rendered as a literal character and the bare double-quote still closes the attribute. This makes it possible for authenticated attackers with Administrator-level access and above to inject arbitrary web scripts in the admin settings page that will execute whenever any administrator visits the General Options settings page.

How severe is CVE-2026-6399?

CVE-2026-6399 has a CVSS score of 4.4/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2026-6399?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.