# CVE-2026-81780: Hash Form arbitrary file upload

Source: https://junglewise.ai/threats/cve-2026-81780-hash-form-arbitrary-file-upload  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-31. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-81780 · Severity: critical · CVSS 10 · Published 2026-08-31

Hash Form is a WordPress plugin used to create customizable forms on websites. The plugin contains an unauthenticated file upload vulnerability that allows attackers to upload malicious files to the server without logging in, potentially leading to complete server compromise and website takeover. This is a critical risk affecting any WordPress site using vulnerable versions of the plugin.

Technologies: [HashThemes Hash Form](https://junglewise.ai/threats/technologies/hash-form). Vendors: [HashThemes](https://junglewise.ai/threats/vendors/hashthemes).

## Quick answers

**Is CVE-2026-81780 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-81780 being exploited in the wild.

**How severe is CVE-2026-81780?** Critical severity, with a CVSS score of 10, published 31 August 2026.

**Which products and versions are affected?** HashThemes Hash Form <=1.4.2.

**Is there a fix for CVE-2026-81780?** A patch was published on 2026-08-28: Patched in version 1.4.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-81780 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-81780?** Check whether you run HashThemes Hash Form 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 vulnerability is an unauthenticated arbitrary file upload flaw in the Hash Form WordPress plugin versions 1.4.2 and earlier. The vulnerability allows attackers to upload malicious files to the server without authentication, due to missing or inadequate file upload validation. An attacker can exploit this over the network by submitting a file upload request to the vulnerable endpoint. Once a malicious file is uploaded, the attacker can execute arbitrary code on the server, leading to full server compromise. The vulnerability has been patched in version 1.4.3 and later.

## Affected products

- HashThemes Hash Form <=1.4.2

## Timeline

- 2026-08-28: disclosed: Vulnerability reported to Patchstack
- 2026-08-31: advisory: CVE-2026-81780 published
- 2026-08-28: patched: Patched in version 1.4.3

## References

- [https://wordpress.org/plugins](https://wordpress.org/plugins)
- [https://patchstack.com/database/wordpress/plugin/hash-form/vulnerability/wordpress-hash-form-plugin-1-4-2-arbitrary-file-upload-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/hash-form/vulnerability/wordpress-hash-form-plugin-1-4-2-arbitrary-file-upload-vulnerability?_s_id=cve)

## Related threats

- [Hash Form PHP object injection vulnerability](https://junglewise.ai/threats/cve-2026-78292-hash-form-php-object-injection-vulnerability)
- [HashThemes Hash Form cross-site request forgery](https://junglewise.ai/threats/cve-2026-78280-hashthemes-hash-form-cross-site-request-forgery)