Quick answers
- Is CVE-2026-12978 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-12978 being exploited in the wild.
- How severe is CVE-2026-12978?
- Informational severity, with a CVSS score of 7.1, published 16 July 2026.
- Which products and versions are affected?
- FunnelKit Funnel Builder < 3.15.0.6.
- Is there a fix for CVE-2026-12978?
- A patch was published on 2026-06-25: Fixed in version 3.15.0.6 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-12978 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-12978?
- Check whether you run FunnelKit Funnel Builder at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The FunnelKit plugin fails to sanitize the 'input_size' parameter within the 'et_wfop_optin_form' AJAX action before reflecting it into an HTML response. This action is registered when the Divi theme or builder is active and lacks proper nonce or capability checks. An attacker can craft a POST request (requiring 'et_load_builder_modules=1' to trigger the module load) that injects a script into a <style> block by closing the tag. When a logged-in user, such as an administrator, is induced to submit this request via a malicious page, the injected script executes in their browser session. This vulnerability was fixed in version 3.15.0.6.
Affected products
- FunnelKit FunnelKit Funnel Builder < 3.15.0.6
Timeline
- 2026-06-25: disclosed: Initial public disclosure by WPScan
- 2026-06-25: patched: Fixed in version 3.15.0.6
- 2026-07-16: advisory: CVE-2026-12978 published to NVD