CVE-2026-100159 json
Popup Box 6.4.1 - 6.4.2 - Unauthenticated Arbitrary Shortcode Execution via Client-IP / X-Forwarded-For HTTP Headers
published 2026-10-16 24 d ago modified 2026-10-16 23 d ago also EUVD-2026-102592
- cvss
- 4.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 17%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 23 d ago
Exploit prediction
0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N |
Affected products
- ays-pro Popup Box – Create Countdown, Coupon, Video, Contact Form Popups
Classification
- Weakness
-
- CWE-94 Improper Control of Generation of Code
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/535c4796-d1aa-4cd1-922e-f9dcf216f76d?source=cve
- plugins.trac.wordpress.org /browser/ays-popup-box/tags/6.4.2/public/class-ays-pb-public.php#L3389
- plugins.trac.wordpress.org /browser/ays-popup-box/tags/6.4.2/public/partials/ays-pb-public-templates.php#L4560
- plugins.trac.wordpress.org /browser/ays-popup-box/tags/6.4.2/public/partials/ays-pb-public-templates.php#L4299
- plugins.trac.wordpress.org /browser/ays-popup-box/tags/6.4.2/includes/class-ays-pb-data.php#L79
- plugins.trac.wordpress.org /browser/ays-popup-box/tags/6.4.2/public/partials/ays-pb-public-templates.php#L69
- plugins.trac.wordpress.org /browser/ays-popup-box/tags/6.4.3/public/class-ays-pb-public.php
Sources
- CVE List CVE-2026-100159
- NVD CVE-2026-100159
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.