CVE-2026-100159
Popup Box 6.4.1 - 6.4.2 - Unauthenticated Arbitrary Shortcode Execution via Client-IP / X-Forwarded-For HTTP Headers
Description
The Popup Box plugin for WordPress is vulnerable to Arbitrary Shortcode Execution in versions 6.4.1 to 6.4.2. This is due to the ays_popup_get_user_ip() function reading the client-controlled Client-IP / X-Forwarded-For / Forwarded / X-Forwarded / Forwarded-For request headers, sanitizing them only with sanitize_text_field() (which does not strip the bracket, quote, space, or '=' characters used by shortcode syntax), substituting the value into a popup body wherever the %%user_ip_address%% token appears (a raw str_replace with no escaping in Ays_Pb_Data::replace_message_variables()), and then passing the resulting body to do_shortcode() in Ays_Pb_Public::ays_autoembed() at output on the wp_footer hook. This makes it possible for unauthenticated attackers to execute arbitrary registered shortcodes with attacker-supplied attributes on the server whenever an administrator has added the %%user_ip_address%% token to a popup's Custom Content body, which can be leveraged to read arbitrary data or perform other actions exposed by shortcodes installed on the site.
INFO
Published Date :
Oct. 16, 2026, 3:17 a.m.
Last Modified :
Oct. 16, 2026, 3:17 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-100159
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Popup Box plugin to the latest version.
- Remove %%user_ip_address%% token from popup content.
- Review site for any unauthorized shortcode executions.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-100159.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-100159 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-100159
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-100159 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-100159 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Oct. 16, 2026
Action Type Old Value New Value Added Description The Popup Box plugin for WordPress is vulnerable to Arbitrary Shortcode Execution in versions 6.4.1 to 6.4.2. This is due to the ays_popup_get_user_ip() function reading the client-controlled Client-IP / X-Forwarded-For / Forwarded / X-Forwarded / Forwarded-For request headers, sanitizing them only with sanitize_text_field() (which does not strip the bracket, quote, space, or '=' characters used by shortcode syntax), substituting the value into a popup body wherever the %%user_ip_address%% token appears (a raw str_replace with no escaping in Ays_Pb_Data::replace_message_variables()), and then passing the resulting body to do_shortcode() in Ays_Pb_Public::ays_autoembed() at output on the wp_footer hook. This makes it possible for unauthenticated attackers to execute arbitrary registered shortcodes with attacker-supplied attributes on the server whenever an administrator has added the %%user_ip_address%% token to a popup's Custom Content body, which can be leveraged to read arbitrary data or perform other actions exposed by shortcodes installed on the site. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Added CWE CWE-94 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/100xxx/CVE-2026-100159.json">CVE-2026-100159</a> Added Reference https://plugins.trac.wordpress.org/browser/ays-popup-box/tags/6.4.2/includes/class-ays-pb-data.php#L79 Added Reference https://plugins.trac.wordpress.org/browser/ays-popup-box/tags/6.4.2/public/class-ays-pb-public.php#L3389 Added Reference https://plugins.trac.wordpress.org/browser/ays-popup-box/tags/6.4.2/public/partials/ays-pb-public-templates.php#L4299 Added Reference https://plugins.trac.wordpress.org/browser/ays-popup-box/tags/6.4.2/public/partials/ays-pb-public-templates.php#L4560 Added Reference https://plugins.trac.wordpress.org/browser/ays-popup-box/tags/6.4.2/public/partials/ays-pb-public-templates.php#L69 Added Reference https://plugins.trac.wordpress.org/browser/ays-popup-box/tags/6.4.3/public/class-ays-pb-public.php Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/535c4796-d1aa-4cd1-922e-f9dcf216f76d?source=cve