CVE-2026-111255: File Upload RCE (CVSS 7.5)

Description

The affiliate-toolkit – Multi-Network Affiliate & Amazon Product Display plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 3.9.2 via the upload_image function. This is due to insufficient file type validation in upload_image due to a weak Content-Type prefix check and extension derivation from the attacker-controlled URL path, with no dangerous-extension stripping. This makes it possible for authenticated attackers, with contributor-level access and above, to upload files that may be executable, which makes remote code execution possible. Exploitation requires the "import product image" option to be enabled in the plugin settings, as this activates the image download pipeline triggered on product post save.

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CVSS v3.1 Score

7.5

HIGH

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

EPSS — Exploit Prediction

0.0052

Probability of exploitation

0.44%

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-434 Unrestricted Upload

References

Other References

https://plugins.trac.wordpress.org/browser/affiliate-toolkit-starter/tags/3.9.2/includes/atkp_posttypes_product.php#L3192 https://plugins.trac.wordpress.org/browser/affiliate-toolkit-starter/tags/3.9.2/includes/basics/ATKPTools.php#L546 https://plugins.trac.wordpress.org/browser/affiliate-toolkit-starter/tags/3.9.2/includes/basics/ATKPTools.php#L657 https://plugins.trac.wordpress.org/browser/affiliate-toolkit-starter/tags/3.9.2/includes/basics/ATKPTools.php#L710 https://plugins.trac.wordpress.org/browser/affiliate-toolkit-starter/tags/3.9.2/includes/dataservices/atkp_productservice.php#L775 https://plugins.trac.wordpress.org/changeset?reponame=&old=3759575%40affiliate-toolkit-starter&new=3759575%40affiliate-toolkit-starter https://www.wordfence.com/threat-intel/vulnerabilities/id/272a8ee4-8689-4935-89c5-e2f502621511?source=cve

Frequently Asked Questions

What is CVE-2026-111255? +

The affiliate-toolkit – Multi-Network Affiliate & Amazon Product Display plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 3.9.2 via the upload_image function. This is due to insufficient file type validation in upload_image due to a weak Content-Type prefix check and extension derivation from the attacker-controlled URL path, with no dangerous-extension stripping. This makes it possible for authenticated attackers, with contributor-level access and above, to upload files that may be executable, which makes remote code execution possible. Exploitation requires the "import product image" option to be enabled in the plugin settings, as this activates the image download pipeline triggered on product post save. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-111255? +

CVE-2026-111255 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0052, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-111255? +

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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