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HuttenlocherTechnologies
HighCVSS 8.1WordPress plugins & themes

CVE-2026-5436

MW WP Form: Arbitrary File Move/Read

The MW WP Form plugin for WordPress is vulnerable to Arbitrary File Move/Read in all versions up to and including 5.1.1. This is due to insufficient validation of the $name parameter (upload field key) passed to the generate_user_file_dirpath() function, which uses WordPress's path_join() — a function that returns absolute paths unchanged, discarding the intended base directory. The attacker-controlled key is injected via the mwf_upload_files[] POST parameter, which is loaded into the plugin's Data model via _set_request_valiables(). During form processing, regenerate_upload_file_keys() iterates over these keys and calls generate_user_filepath() with the attacker-supplied key as the $name argument — the key survives validation because the targeted file (e.g., wp-config.php) genuinely exists at the absolute path. The _get_attachments() method then re-reads the same surviving keys and passes the resolved file path to move_temp_file_to_upload_dir(), which calls rename() to move the file into the uploads folder. This makes it possible for unauthenticated attackers to move arbitrary files on the server, which can easily lead to remote code execution when the right file is moved (such as

Description from the National Vulnerability Database, published by Wordfence

What to do: Affects up to 5.1.1. Update MW WP Form to the newest version and check its changelog mentions this fix; if there isn’t one yet, deactivate it until there is.

What it means for a small business

MW WP Form is a WordPress plugin. If your website uses it, the flaw is on your site whether or not anyone has noticed yet: attackers scan the whole internet for the plugins with published flaws, usually within days of a record like this one going public.

Most small-business sites run 15 to 40 plugins, and few owners know the list. You can check from WordPress itself (Plugins, then Installed Plugins), or let our free plugin check look it up by name.

Check your own setup

  • Is MW WP Form on the danger list? Our free plugin check shows every recorded flaw for it and the version that fixes each.
  • Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
  • Server check: what your web server says about itself, and whether that version has known flaws.

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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