CVE-2026-3853

MEDIUM
Published Sep 5, 2026 Modified Sep 8, 2026 CWE-79

Description

The Divi theme for WordPress is vulnerable to DOM-Based Stored Cross-Site Scripting via the `image_src` attribute of the `et_pb_video_slider_item` shortcode in all versions up to, and including, 4.27.6. This is due to the `image_src` field not being included in the `$url_options` whitelist (which only contains `url`, `button_link`, `button_url`), so it never receives `esc_url_raw()` at save time. On the server side, the value is rendered into a `data-image` HTML attribute using `esc_attr()`, which encodes double quotes as `"`. However, the client-side JavaScript carousel code in `custom.unified.js` reads this attribute using jQuery's `.data('image')`, which returns the browser-decoded value (with `"` decoded back to `"`). The decoded value is then concatenated directly into an HTML string and injected into the DOM via `jQuery.after()` without re-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 hovers over the carousel thumbnail.

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CVSS v3.1 Score

6.4
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0017
Probability of exploitation
0.06%
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

Frequently Asked Questions

What is CVE-2026-3853? +
The Divi theme for WordPress is vulnerable to DOM-Based Stored Cross-Site Scripting via the `image_src` attribute of the `et_pb_video_slider_item` shortcode in all versions up to, and including, 4.27.6. This is due to the `image_src` field not being included in the `$url_options` whitelist (which only contains `url`, `button_link`, `button_url`), so it never receives `esc_url_raw()` at save time. On the server side, the value is rendered into a `data-image` HTML attribute using `esc_attr()`, which encodes double quotes as `"`. However, the client-side JavaScript carousel code in `custom.unified.js` reads this attribute using jQuery's `.data('image')`, which returns the browser-decoded value (with `"` decoded back to `"`). The decoded value is then concatenated directly into an HTML string and injected into the DOM via `jQuery.after()` without re-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 hovers over the carousel thumbnail. It has a CVSS v3.1 base score of 6.4 (MEDIUM).
How severe is CVE-2026-3853? +
CVE-2026-3853 has a CVSS v3.1 score of 6.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0017, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-3853? +
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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